Cellular Respiration Experiment

Cellular Respiration Experiment
roduction
This experiment tested the hypothesis that there is no difference between before exercise and after exercise in terms of cellular
respiration rates. The purpose of this experiment is to compare the rates of cellular respiration before and after vigorous
exercise. During cellular respiration, glucose is broken down into CO2 (carbon dioxide). As CO2 (carbon dioxide) is bubbled
through water, H2CO3 (carbonic acid) is formed. Because H2CO3 (carbonic acid) is a weak acid and dissociates in water, it
forms HCO3– and H+ ions. As a basic solution is partially neutralized by an acid, phenolphthalein turns clear. Measuring the
relative rates of the production of carbon dioxide before and after exercise can help us compare the rates of cellular respiration.
We can estimate the rates of cellular respiration by measuring how much time it takes for the phenolphthalein to change color
because the carbon dioxide we exhale would react with the water in the solution to form carbonic acid. Then the carbonic acid
would neutralize the NaOH in the solution and would turn colorless when enough acid ... Show more content on
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The "before" and "after" samples were produced with the same concentrations at the same time. First, 220 ml of H2O is
measured in a graduated cylinder and poured into an Erlenmeyer flask. Then, 5 drops of 10% sodium hydroxide and 3 drops of
phenolphthalein is added and swirled gently together. Next, the solution is aliquoted into two 250 ml Erlenmeyer flasks with
100 ml in each flask. The subject inserted a straw into the solution of one flask and blown gently through the straw. The
observer watched carefully and recorded the number of seconds it took for the solution to change from pink to clear. The
resting time is recorded and the subject exercised vigorously for five minutes. The subject repeated the blowing process
through the straw using the second flask and the observer recorded the time it took for the solution to turn
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Phenolphthalein Lab
In this lab, we examined cubes of phenolphthalein submerged in Sodium hydroxide to see what the effects would be. For the
phenolphthalein, we used Agar cubes cut in three different sizes: small, medium and large. The purpose of this Lab was to
study the surface area to volume ratio in cells and see how this ratio affects cell size. Phenolphthalein (C20H14O4) is one of
the most common acid–base indicators used to determine the end point in acid–base titrations. Sodium hydroxide (NaOH) is an
inorganic compound also known as lye. When exposed to each other, these two compounds made the Agar cubes turn magenta
(pink). Diffusion occurs along diffusion gradients going from areas of high concentration to areas of lower concentration. So
with time the NaOH diffuses from the area of high concentration outside of the agar cube to areas of lower concentration inside
of the cube. Once the Agar cubes had been immersed in the NaOH for ten minutes, we cut each cube in half. The depth of
diffusion on each of the cubes was .3 cm. * The rate of diffusion for all three agar cubes was .03 ... Show more content on
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Cells need to metabolize nutrients and excrete waste in order to live. These processes need to occur efficiently. On the agar
cubes, the pink area represents the depth of diffusion and indicates how far nutrients diffusing into the cell would travel. The
percentage of pink area indicates how efficient the diffusion is. The white area is bad because this means there was no diffusion
into that region. In theory, any cube with a white area will die since that portion of the cell would not acquire the necessary
nutrients. The small cube was the most efficient at gaining nutrients and getting rid of waste as almost all of the cube had
turned pink. In conclusion, the best cell size was the small cube because it had the larges SA:Vol ratio and therefore, it had the
most diffusion. Cells need a large SA:Vol ratio to stay alive, that is why they are microscopic in

Rebreathing Carbon Dioxide Graph Lab Report
Comparing my Rebreathing Carbon Dioxide graph to my peers, I noticed that we all share an increase in both the breathing
rate and depth. Talking to my peers, I noticed that we all mutually had the pressure of the pressure cuff go down once we
finished this experiment. This release of pressure most likely occurred because during the different intervals – breathing
normally, holding our breaths, slowly breathing, and breathing through the Ziploc bag – the kPa, or unit of pressure, gradually
decreased. The relationship between breathing rate and breathing depth is that they strongly influence HRV, or heart rate
variability. This is most efficient because the tidal volume decreases as heart rate does too, although the changes are
insignificant. For example, when you exercise, both ... Show more content on Helpwriting.net ...
This might have happened because as we breathe normally, At the start of C, E was more staggered, as it differed from person
to person. For some, their breathing rate shot up, while for others, their breathing rate went down. These staggered results
could be because we held out breaths for a minute and a half, where one's heart rate would increase. This is because the body
desires to get rid of the carbon dioxide accumulating in the lung's alveoli and to take in more oxygen so that more and more
body cells can get the nutrients they need to properly function. The blood pH levels in B decreases as we hold our breaths
because of an increase in hydrogen ions and carbon dioxide in the blood. The pH of blood in D decreases as we rebreathe the
carbon dioxide because the carbon dioxide building up in our lungs is trying to be exhaled and the oxygen in the body are
trying to reach the body cells or the lungs. An increase in breathing rate, such as in D, decreases the level of carbon dioxide
concentration and increases oxygen concentration, thus causing a decrease in hydrogen

Quality Control Technique
Introduction
Quality control is a technique used to evaluate objects that people use on a day–to–day basis. This technique is used to evaluate
the ingredients in food and see if they are accurate. The objective of this quality control experiment was to examine different
acid and base materials and test their pH levels. As a part of the experiment, a procedure was formed to create NaOH and HCl
standard solutions and then conduct acid–base titrations to decipher between the acid–base materials. The standard solutions
were used to dilute the acid–base materials for the titrations and then test what pH level each one possessed. Titration was used
"for determining the quantity or concentration of a substance in a solution" (Dartmouth College, 1997). In this experiment, the
substances were the acid or base materials. As a hypothesis, the standard solution NaOH was going to determine the acidic
substance and the HCl solution was going to determine the basic substance.
Methods
Materials– As a group, proper lab attire was worn at all times. Once the lab bins were obtained, other materials were retrieved
and brought back to the lab bench. The materials included pH strips and reagent chemicals such as phenolphthalein and
bromothymol blue. These reagent chemicals emanate a certain color to help determine whether each substance was an acid or a
base. According to Senese (1997), Bromothymol turns blue when it comes in contact with a base and phenolphthalein turns
pink when it comes in

Essay on Laboratory Techniques and Measurements
Title
Laboratory Techniques and Measurements
Purpose
The purpose of this experiment is to determine mass, length, temperature, volume, and density of objects and liquids using
common measuring devices and algebraic formulas. The metric system, the most common set of measurements used in
science, which includes meters, liters, Celsius, and grams will be used.
Procedure
The following items were used within the experiment:
(1) Metric ruler with centimeter (cm) and millimeter (mm), (1) table salt, (1) small number of ice cubes, (1) piece of string, (1)
isopropyl (rubbing) alcohol, (1) tap water, (1) distilled water, 25 mL, (1) paper, 5 cm x 5 cm for weighing chemicals, (1)
colored drink, (1) beaker, 100 mL, glass (1) ... Show more content on Helpwriting.net ...
(NH4OH was used instead of NH3 because it was not available.)
An empty and distilled cleaned pipet was used to drop substances on the paper.
Observations / Data Table 1
Chemicals Well # Reaction on White Paper Reaction on Black Paper
NaHCO3
(sodium bicarbonate) HCL
(Hydrochloric Acid) A1 Mixture absorbed within paper within seconds; Clear bubbles appeared within the product; stained
clear Clear bubbles within the product; Product was slow to absorb into paper; once substance was absorbed, the paper stained
green
HCL
(Hydrochloric Acid) BTB
(bromthymol blue)a A2 Mixture beads on paper; Appears orange; Slow to absorb mixture; color changed green and dried
yellow–tan with a green border
NH3
(Ammonia) BTB
(bromthymol blue) A3 Mixture absorbed within paper within seconds; appears blue Absorbed immediately; Appears blue
HCL
(Hydrochloric Acid) Blue Dye A4 Mixture absorbed within paper within seconds; Substance appears green Slow to absorb
mixture; did not change color of paper; Dried Green and tan
Blue Dye NaOCl
(sodium hypochlorite) A5 Mixture absorbed within paper within seconds; Aquablue Slow to absorb mixture; Green with
yellow border
**Forgot to add 1 drop of HCl
NaOCl
(sodium hypochlorite) KI
(potassium iodide) A6 Mixture absorbed within paper within seconds; Yellow Slow to absorb mixture; Yellow
Add 1 drop of

Analysis of Soda Ash and Carbonate-Bicarbonate Mixture
Analysis of Soda Ash and Carbonate–Bicarbonate Mixture
Submitted: February 27, 2013
Department of Chemical Engineering, Faculty of Engineering
University of Santo Tomas
España, Manila
Abstract
A standard acid solution like HCl can be used as titrant for the analysis of both soda ash and a carbonate–bicarbonate mixture.
In the analysis of soda ash, the volume needed to neutralize the soda ash is used to compute for its alkalinity, in this experiment
we obtained a 17.6 % alkalinity with an error of 15.14% In the analysis of a carbonate–bicarbonate mixture two indicators
(phenolphthalein and methyl orange) were used. The first endpoint determines the half–neutralization of the carbonate and the
second determines that of the ... Show more content on Helpwriting.net ...
Three trials were made and the average percentage alkalinity was reported.
Analysis of Carbonate–Bicarbonate Mixture For this experiment, a pH meter was used so this part of the experiment began
with the calibration of the pH meter with specified buffers. The buret was then filled with the standard HCl solution and a set–
up for titration was prepared. 200g of the carbonate–bicarbonate solid sample was weighed and dissolved in 100 mL of
distilled water. The sample solution was then transferred into a 250–ml volumetric flask and was diluted to the 250–mL mark.
The flask was inverted several times for uniform mixing. A 50–mL aliquot of the sample solution was measured and placed
unto a beaker. 3 drops of the phenolphthalein indicator was added to the solution in the beaker. The electrode of the pH meter
was then immersed in the beaker and the solution containing the carbonate–bicarbonate mixture was titrated with the standard
HCl solution to the phenolphthalein endpoint. Readings of the pH were taken at an interval of 0.5 mL addition of the titrant.
After the first endpoint is obtained, 3 drops of the methyl orange was added to the same solution and was titrated with the
standard acid until the formation of an orange–colored solution. Readings of the pH were also taken at 0.5 mL addition of the
titrant. Results and Discussion
In the standardization of the HCl solution, the

How Much Sodium Hydroxide Used To Turn The Diluted Vinegar
HNC Applied Sciences
Zakiah Ali
Aim
The aim of this experiment was to measure how much sodium hydroxide was used to turn the diluted vinegar pink.
Materials
2 Pipettes (25cm3)
Burette
Volumetric flask
2 beakers
Clamp stand
Clip
White title
Funnel
Conical flask
Pipette filler
Vinegar
Deionised water
0.1mol/l sodium hydroxide
3 drops of phenolpththalein indicator
Summary
A standardized vinegar solution was prepared, to test how much sodium hydroxide is needed to turn the solution pink. In order
to know when the equivalence point is reached, an indicator solution called phenolphthalein was added to the vinegar at the
start of the titration. Phenolphthalein is an organic dye which is colorless in acidic solutions ... Show more content on
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The hose of the burette was opened until the solution turned pink. 20.2ml of sodium hydroxide was used to get the solution to
turn pink.( 4. Fill the burette with NaOH (aq) up to the top, between 0–mL and 5–mL. Use a funnel to do this carefully,
preferably over the sink. Measure this volume precisely, and record it as the "Initial Burette Reading" on your

Compound Reactions Write-Up
Chemistry – Group I & II Compound Reactions Write–up
Aim: To discover how the three groups of elements react with water and oxygen and the relationships and reaction similarities
between the three groups.
Hypothesis: As the present element used moves down in groups the substance or compound will react more readily, and groups
II and III will react less readily than group I, thus dissolving slower or not at all.
Equipment:
30 test tubes
Test tube rack
Bunsen Burner
Tripod
Heat–proof mat
Tongs
Universal Indicator
Phenolphthalein
Demineralised water
Stirring rod/Spatula
Large Bowl
Elements and compounds:
Lithium (Li) Sodium (Na) Potassium (K)
Lithium Oxide (Li2O) Sodium Oxide (Na2O) Potassium Oxide (K2O)
Lithium Chloride (LiCl) Sodium Chloride (NaCl) Potassium Chloride (KCl)
Lithium Carbonate (Li2CO3) Sodium Carbonate (Na2CO3) Potassium Carbonate (K2CO3)
Lithium Sulfate (Li2SO¬¬4) Sodium Thiosulfate (Na2S2O3) Potassium Sulfate (K2SO¬4)
Lithium Hydroxide (LiOH) Sodium Hydroxide (NaOH) Potassium Hydroxide (KOH)
Magnesium (Mg) Calcium (Ca) Barium (Ba)
Magnesium Oxide (MgO) Calcium Oxide (CaO) Barium Oxide (BaO)
Magnesium Chloride (MgCl2) Calcium Chloride (CaCl¬2) Barium Chloride (BaCl2)
Magnesium ... Show more content on Helpwriting.net ...
Soft enough to cut with the edge of a coin When reacting to oxygen (O2) a chemical reaction occurs causing Sodium (Na) to
become Sodium Oxide (Na¬2O) presenting a white crystallised substance. Burns with oxygen to provide a bright yellow flame
Sodium (Na) reacts vigorously and also creates heat and Hydrogen gas (H), becoming Sodium Hydroxide (NaOH). The
reaction was more severe than that of lithium, causing the substance to skip across the water on a cloud of Hydrogen Gas (H)
After reacting with H2O and becoming NaOH, Phenolphthalein is added and creates a pink colour indicating a base is

Titration Of A Concentration And The Acid Base Titration
Summary
The purpose of this experiment was to find the molarity of a concentration and the acid–base titration. In part A of this
experiment, the molarity of an assigned concentration which was 0.040, was found using formulas that represent molarity. Part
B of this experiment, which was titration of an acid and base, was found by a series of steps that involved dropping Sodium
Hydroxide from a buret into vinegar, until the perfect shade of pale pink occurred. With the Phenolphthalein, too much acid
causes the base to turn a dark pink. The molarity was then found of the titration. So the end results will determine M HCH3O2.
Introduction A solution is a homogenous mixture of a solvent and one or more solutes. The substance that dissolves in the
solute is the solvent, and the solute is what gets dissolved. Solutions can vary in concentration in great ratio differences. It is
very important to be able to correctly prepare solutions. There is always a proper amount of solution to be made to have a
desired amount of produced. So in the medical world, too much solute will most likely have harmful effects like overdosing
and too little could result in ineffective treatment. Also the money spent on solutions could also be another reason for correct
preparation of solutions, because the success of the drug has an effect on future sales and profit. Solutions that are dilute, are
weak, and solutions that are concentrated are strong. A precise means of describing concentration is 1.

Essay on Lab Report
Richmonde Zegbe
CHM111
Anita Mohan
03–11–2013
Experiment: Chemical reactions, and Equations
Materials:
3 mL of copper(II) sulfate solution. 5 mL of 6 M HCl piece of zinc wooden splint test tube Bunsen burner 3 mL of zinc
chloride solution. pentahydrate distill water 0.1 g of ammonium dichromate phenolphthalein tongs strip of magnesium spatula
NaOH ... Show more content on Helpwriting.net ...
Add a dropperful of 1.0 M hydrochloric acid.
PART 2: Redox Reactions
Combination reactions
A1.Work under the hood! With a pair of tongs, hold a strip of magnesium in a bunsen burner flame. Do not look directly at the
flame. Save the ash in a small beaker for the next procedure. If magnesium is substance "A" in the general equation, what is
"B"?
A2. Add a dropperful of distilled water and a drop of phenolphthalein. The phenolphthalein is only an indicator for the
presence of hydroxide ion and does not enter into the equation. Decomposition reactions
B1. Work under the hood! Weigh out exactly 0.1 g of ammonium dichromate and add to a test tube. Clamp and warm gently
with a Bunsen burner. Two of the products of this reaction are chromium(III)oxide and nitrogen gas. Watch for evidence of the
third product.
B2.Place a few crystals of copper(II)sulfate pentahydrate in a test tube. Clamp the tube and heat in a horizontal position. One
of the products is copper(II)sulfate. What is the other one? This decomposition reaction is easily reversible. Add a dropperful
of water to the tube when it cools. Record what happens.
Replacement reactions
C1.Work under the hood! Place a piece of zinc in a test tube. Add about 5 mL of 6 M HCl and allow the zinc to effervesce.
Ignite a wooden splint in a Bunsen burner flame and hold this flame to the mouth of the test tube. If hydrogen is generated as
one of the

Titration : An Acid Base Titration
3. Titration: A technological process in which a solution, known as the titrant, is added to another solution, called the sample,
until the reaction is judged to be complete. In an acid–base titration, an acid neutralizes a base or vice versa.
Endpoint: The point in a titration analysis at which the addition of the titrant is stopped due to an observable colour change
seen through the presence of an indicator in the sample. The colour changes is a result of rapid pH change in the sample.
Equivalence point: the point in a titration analysis at which chemically equal amounts of titrant and sample (acid and base)
have been combined.
4. It would be easiest to measure a different pH then what was predicted when the volume of HNO3 added is 25mL, this is
because the PH drops rapidly from 11.61 to 2.4 with the addition of a single mL. However, we cannot predict a PH value at this
time either, because that would require finding the –log of zero which is mathematically impossible. Thus we can only predict
that the pH will fall somewhere between 11.61 and 2.4.
5. a) H2SO4 is a strong acid just like HNO3 but it is a polyprotic acid meaning that their will be two proton transfer reactions
and thus two equivalence points. b) The graph will be mirrored, so that the PH levels go from low to high rather than high to
low, because the sample is now an acid becoming more basic not a base becoming more acidic.. c) The use of a weak base,
causes the equivalence point to occur at a PH of

Investigating the Effect of Lipase Concentration on the...
Investigating the Effect of Lipase Concentration on the Breakdown of Fat in Milk
INTRODUCTION:
Enzymes are proteins which can catalyse chemical reactions without changing themselves. The enzyme lipase breaks down the
fat in dairy products such as full–cream milk for people who are lactose intolerant. Lipase acts on its specific substrate, lipids
produces fatty acids. If enzyme concentration increases, random collisions between the substrates and active sites of enzyme
increase due to the increasing amount of active sites which allow more collisions to happen, so the rate of breakdown of lipids
to simpler substances will increase. During the experiment, sodium carbonate solution and pH indicator phenolphthalein will
be added ahead of ... Show more content on Helpwriting.net ...
If more were placed in one of the test tubes, then the rate of activity of the enzyme at different concentrations will be wrongly
judged, leading to incorrect conclusion.
4. Temperature will be kept consistent at room temperature – All tested will be done in the Biology laboratory with the
windows shut to make sure the temperature will not change during the tests. The higher the temperature, the shorter the time
will be needed for the chemical reactions to happen and phenolphthalein to turn from pink to colourless.
Dependent Variable:
1. The time for the phenolphthalein to turn from pink to colourless will be taken using the stopwatch.
METHOD:
* The apparatus was collected; * The beakers labelled; Solutions of lipase respectively at concentrations of 1%, 2%, 3%, and
4% were made using lipase at 5% and distilled water. * By using the dropper and measuring cylinder, an amount of 5ml milk
was placed in the test tube * By using the dropper and measuring cylinder, 10ml phenolphthalein was added to the test tube *
By using the dropper and measuring cylinder, 7 ml sodium carbonate solution was added to the test tube * By using the
dropper and measuring cylinder, 3ml of 1% lipase was added into the test tube * As long as the lipase was added, the button
"start" on the stopwatch was pressed; and the

Enzyme Assay Lab Report
Enzymes are biological catalysts that are involved in important pathways that allow the chemical reaction to occur at higher
rates than would be possible without the enzymes. Enzymes are globular proteins that are responsible for biochemical reactions
within cells and microorganism, these large proteins have more than one substrate binding sites allowing larger volumes of
products to be produced. Enzyme assays are fundamental tools for measuring cellular activity and for monitoring enzyme
protein while it's being purified. Measurement of enzyme kinetics provides crucial information on the mechanism of enzyme
catalysis and on the interaction of an enzyme substrate, inhibitors and drugs. The essential requirement for enzyme assay is
described ... Show more content on Helpwriting.net ...
Enzymes were added after the addition of sodium carbonate (Na2CO3) to tube 0 (also referred as the control tube) as this
allows to compare it to the other groups. The control is an experimental design to help minimise the effects of variables other
than the dependent variable thus, increases the reliability of the results.
The purpose of Part B was to determine the unknowns in the experiments. The substrate used in the enzyme assay is
phenolphthalein monophosphate, the coloured produced being phenolphthalein. Phenolphthalein monophosphate is used
initially in part to determine the initial velocity where part C it was used to determine the rate of phenolphthalein produced vs
the pH levels. To conduct the experiment a standard curve of phenolphthalein is made to find the relationship between the
concentration and absorbance at 520nm. This will implement easy calculations of the concentrations of the product is formed
in part

Interactions Of Group 1 And 2 Elements And Their Compounds...
Stage 1 Chemistry
Reactions of Group I and II Elements and Their Compounds.
Results:
Reactions of Group I Elements
Chemical Observations Appearance Colour when Phenolphthalein was added
Lithium Before added to the H²O it had already acted with the oxygen creating lithium oxide. When added to the H2O the
piece of Lithium starts to bubble (sizzle), produces heat, and dissolves . Looks like a piece of chalk, and is grey/silver in the
middle once it has been cut open. Very soft to cut. Turns to Lithium Hydroxide as the H2O turns pink.
Sodium and Phenolphthalein When added to the H2O the small piece of Sodium goes out of control (spazzes), rolls on top of
the H2O, produces heat and melts. Makes a loud buzzing sound and also turns into Looks like ... Show more content on
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Water goes powdery
Magnesium carbonate MgCO3 White powder like substance pH9.5 Doesn't dissolve goes milky
Magnesium oxide MgO White powder like substance pH9.8 Doesn't dissolve. Liquid is powdery and clear.
Barium Chloride BaCl2 White sugar like substance pH7 Dissolves into a clear liquid
Barium Hydroxide Ba(OH)2 White powder like substance pH11 Doesn't dissolve water is clear but powdery
Calcium Chloride CaCl2 White small rock like substance pH11 Sticky, dissolvable
Magnesium sulphate MgSO4 Clear crystal like substance pH7.2 Dissolves and water stays clear
Barium carbonate BaCO3 White/yellow power like substance pH7.8 Doesn't dissolve, water goes milky/clear
Magnesium Chloride MgCl2 Salt Shape like substance pH8.2 Dissolvable water stayed clear
Discussion:
The lower the metal is in the group the faster it will react with water. This was seen to be true for both groups one and two. In
all cases the metals reacted to form Hydrogen Gas ad a solution that was alkaline. Down the group the electronegativity
decreases which results in a metal element losing its valance electrons more easily and hence reacting more

Introduction To Identity The Unknow Acid Solution
The purpose of this experiment is to identity the unknow acid solution through determining the Ka value of the reaction
experimentally. The colors of unknown acid 3 matches the colors of test tube 1, with thymol blue being light pink, malachite
green being dark green and crystal violet being cyan. Comparing it to other 3 test tubes, test tube 2 has a similar result. Both
test tube 3 and 4 have higher Ph than 1 and 2, since thymol blue is yellow and crystal violet is purple in test tube 3, rose and
blue in test tube 4. Crystal violet is green in test tube 2, which shows that it has a lower ph than test tube 1. So, the order of
acidity from most acidic to least acidic is 2143. Dichloroacetic acid is the second strongest in those 4 acids; this suggests that
unknown acid 3 is dichloroacetic acid.
Discussion question:
Phenolphthalein is an indicator commonly used in acid–base titration. Explain how the equivalence point of acid–base reaction
can be determined using this indicator. State relevant reactions, pH ranges and qualitative ... Show more content on
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According to Le Chatelier's principle, the equilibrium shifts to the left, making Phenolphthalein colorless. At a high ph level
where the H3O– concentration is low, the equilibrium shifts to the right, showing the pink color of Phenolphthalein. This
allows it to be used in both weak acid–strong base and strong acid–strong base titration. In a weak acid and strong base
titration, the equivalence point would be above 7 due to the reaction occur between the conjugated base and water. This often
makes the pH value detectable by Phenolphthalein. In a strong acid and strong base titration where the equivalence point is 7,
the spike of pH around equivalence point is huge and all indicators at this range change color at the same volume of acid or
base. Therefore, using Phenolphthalein in this case won't cause major

Lab Report Ph Indicator Results
RESULTS
One drop of phenolphthalein indicator was added to each Well in row A and the color of each solution was recorded in Data
Table A. Wells A1 through A4 remained clear and transparent. A5 turned a murky pink. The A5 pencil mark on the paper below
the Wells was still slightly visible. A6 turned a clear light pinkish purple.
The pH of each Well in row B1 to B6 was tested with a pH strip.
B1 turned the pH strip a dark pink or red rose color, the pH was recorded at one. B2 turned the pH strip an orange color that
had a pink hint to it, the pH was recorded at three. B3 turned the pH strip an orange color with a darker ring of orange, almost
red around it, the pH was recorded at four. B4 turned the pH strip a yellow color with a ring of ... Show more content on
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The color in Well C1 was a transparent light pink rose color, the pH was estimated to be between two and three. This estimate
is slightly higher than that of the pH strip test. The color in Well C2 was a transparent redder pink, the pH was estimated to be
around a two. This estimate is slightly higher than that of the pH strip test. The color in Well C3 was transparent and was a
similar color to Well C1 but with lighter orange and pink, the pH was estimated to be around a three. This estimate is slightly
lower than that of the pH strip test. The color in Well C4 was a transparent light green, the pH was estimated to be around a
seven. The estimate of pH from the universal indicator is the same as that of the pH strip test. The color in Well C5 was a
transparent darker green with hints of blue, the pH was estimated to be between a seven and an eight. The estimates are
roughly the same, between all three of the pH tests. The color in Well C6 was transparent was a dark blue, purplish color, the
pH was estimated to be a thirteen or a fourteen. This estimate is slightly higher than that of the other tests, this could be due to
numerous factors. One factor could be that the pH test simply did not reach pH's of 13 and 14, like in the case of the pH strip
test. Another factor is that the first attempt at administering the indicator in Well C6, the drop from the pipette missed and hit

Cellular Respiration Lab Report
Title: Production of Carbon Dioxide, During Aerobic Respiration
Author: Olivia Huertas
Abstract: In this procedure, phenolphthalein will be used to detect changes in pH resulting from the production of CO2 during
cellular respiration. Because phenolphthalein is red in basic solutions and colorless in acidic solutions, you can monitor cellular
respiration by measuring acid production as change in pH. CO2 produced during cellular respiration can combine with water to
form carbonic acid. By measuring the volume of NaOH used to neutralize the carbonic acid produced by the CO2, and thereby
calculate a proximate measure of respiration.
Hypothesis: If the fish and elodea both produce CO2 during cellular respiration, then the Elodea will produce ... Show more
content on Helpwriting.net ...
The solution has been dechlorinated and adjusted to be slightly acidic. Place 75 mL of the solution in each of three labeled
beakers. Obtain an animal organism, small fish, and a plant organism, Elodea. One beaker will be the control and will not have
anything in it. Place exactly 25 mL of water in a 50–mL graduated cylinder. Place each organism in a cylinder and note the
increase in volume above the original 25mL. The increase equals the volume of the organism. After taking measurement, cover
each beaker with the plastic film. Place the beaker containing the Elodea in the dark by covering it with aluminum foil. Allow
organisms to respire for 15 min. Gently remove the organisms from the beakers and return them to their original culture bowls.
Then add four drops of phenolphthalein to the contents of each beaker. The solutions should remain clear because the solutions
are acidic. Using a dropper bottle, dispense NaOH into the contents of the beaker drop by drop. Thoroughly mix the contents of
the beaker after adding each drop. Continue adding drops until you first notice that the solution turns pink. Repeat for each
beaker with at the living organism until the solution is the same shade of pink as the

Chemical Change and Observation Lab
Lab Report 2
Observations of Chemical Changes
Objectives: (1 of 20 points)
The objectives of this experiment are:
1. To observe some properties of chemical reactions
2. To associate chemical properties with household products
Background Information: (2 of 20 points)
Chemical changes are often accompanied by physical changes. Three that you should not see in this lab are changes in
temperature, presence of a flame, and evolution of light, as when as firefly glows. Three physical changes that indicate a
chemical change may have occurred (and that may be seen in this lab) are:
1. Color changes
2. Precipitate (formation of a solid)
3. Formation of gas bubbles
Procedure: (1 of 20 points)
No preliminary dilution of my test chemicals ... Show more content on Helpwriting.net ...
What are chemical changes? Give some examples.
Chemical change results in one or more substances of entirely different composition. Chemical change requires a chemical
reaction.
Burning a log of wood
Mixing an acid with a base, producing water and a salt.
Photosynthesis
Oxidation examples: rust or tarnishing
Combustion
Rotting of fruit
Cooking rice
Explosion of fireworks

Lighting a match
Chewing/digesting food
Burning gas in a stove
Oxidizing food for energy
Roasting a marshmallow
5. What evidences of physical changes have you seen in this experiment?
The tearing of the paper towel into strips; The absorption of the liquid into the paper towel strips (experiment k).
6. What evidences of chemical changes have you seen?
Change in color once chemicals were combined (experiments b,c,d,e,f,g,h,j,l); Precipitate formation (experiments g,j,l), and
formation of gas bubbles (experiment a).
7. Write balanced chemical reactions for reactions a,f,g, and j above.
a. NaHCO3+HClNaCl+H2O+CO2
f. NaOCl+KINaCl+KIO3
g. 2KI+Pb(NO3)2PbI2+2KNO3
j.

The Observation of Chemical Reactions
Department of Chemistry
Submitted by
Date Submitted: 5/30/2012 Date Performed: 5/30/2012 Lab Section: Chem–181DL1 Course Instructor:
Purpose
The purpose of the experiment Observation of Chemical Changes is to examine the properties of chemical reaction and relate
those reactions to products commonly found in a home environment. Through this experiment someone can macroscopically
analyze whether a solution is acidic or base and identify the presence of starches in food.
Procedure
For each of the combinations of chemicals below put 2 drops of each in their own well in the 96–well plate. Making sure to
place only 2 drops of the first chemical then ... Show more content on Helpwriting.net ...
Of the two remaining, one turns slightly yellow, while one remains blue. What can you assume about the acid/base content of
these particular flavors of Vitamin Water?
That the first three sample are neutral, the yellow one is acidic and the blue one is base.
F. You have read that a new brand of hair tonic is supposed to contain lead (an ingredient in
Grecian Formula). Devise a simple test to confirm the presence or absence of lead in that hair tonic.
Mix tonic with potassium iodide and see if solution precipitates yellow.
Observations # | Chemicals | Reaction | A | NaHCO3 & HCI–CO2 | The solution bubbled due to acid/base mixture | B |
HCI & BTB | Turned a yellow–orange revealing acidity | C | NH3 & BTB | Turned blue revealing base, expected
acidic | D | HCI & blue dye | Turned green – acid | E | Blue dye & NaOCI | Turned from blue to green to light yellow
to almost clear–base | F | NaOCI & KI | Turned blackish brown to yellow to black w/ starch | G | KI and Pb(NO3)2 |
Turned to a yellow fog with coagulated appearance | H | NaOH & phenolphthalein | Turned fuchsia– base | I | HCI &
phenolphthalein | Turned foggy to clear and solution churned when mixed–acid | J | NaOH & AgNO3 | Turned foggy thick
brown | K | AgNO3 & NH3 | Turned foggy white to brown when exposed to light | L | NH3 &CuSO4 | Turned thick
foggy aqua blue |

Reaction Rate Of Lipase
Enzymes are substances made of protein that help stimulate chemical reactions. One of the enzymes crucial to human health is
lipase. Lipase is one of the vital digestive enzymes released mainly by the pancreas into the small intestine, to help the body
process and absorb fats. Lipase is a digestive enzyme that breaks down triglycerides into fatty acids and glycerol.
Phenolphthalein is an indicator that is pink in alkaline solutions around pH10. When the pH drops below pH 8.3
phenolphthalein goes colorless. Here, an alkaline solution of milk, lipase and phenolphthalein will change from pink to
colorless as the fat in milk is broken down to form fatty acids (and glycerol) thus reducing the pH to below 8.3. The time taken
for this reaction to occur is affected by temperature.
Temperate affects the reaction rate as when temperature rises, molecules have greater kinetic energy resulting in the molecules
having greater energy than the activation energy, leading to greater enzyme activity. However when the temperatures become
too high the enzymes start to denature leading to slower enzyme activity. Most enzymes have an optimum temperature of 37
degrees.
Aim
To investigate the effect that temperature has on the reaction rate of the lipase with fats in full cream milk.
Hypothesis
The higher the temperature the faster the lipase will react with the fats in full cream milk.
Variables
Independent: The temperate of the water bath
Dependent: Rate of reaction between the lipase

Tartaric Acid Lab Report
The experimental average 〖pk〗_a for the unknown weak acid was 4.075. The experimental average K_a of the unknown
weak acid was 8.424×〖10〗^(–5). The unknown acid was found to be tartaric acid. Tartaric acid has a pK_a value of 2.89 and
a K_a value of 1.288×〖10〗^(–3). The experimental pK_a value had a percentage error of 41.0% when compared to the
theoretical value of pK_a of tartaric acid(equation 8). The experimental K_a value had a percentage error of 93.46% when
compared to the theoretical K_a of tartaric acid(equation 9). These large percentage errors shows that the experimental values
were not accurate. As more NaOH was added to the solution containing tartaric acid, more of the conjugate base was formed
and the pH of the solution will ... Show more content on Helpwriting.net ...
A mass of the unknown acid was weighed out and dissolved in water. The molality of the solution was calculated. This solution
was then titrated using small amounts of the strong acid NaOH. As more NaOH was added to the solution the more the pH
increased. The volume added to solution along with the new pH was using in the Henderson–Hasselbalch

Lab Report : Ph Titration
pH Titration Practical Write Up:
Introduction:
This experiment includes a standard solution, which according to Lewis, R. and Evans, W. "is a solution of known
concentrations". They also stated that "the procedure in finding the concentration of a solution is called volumetric analysis. It
involves reacting a solution of known concentration with one of the unknown concentration, in order to determine the
equivalence point".
Titration is a technique where one reactant is slowly added to a second reagent until the equivalent point is achieved. Chemical
indicators are substances that change their colour at a specific ratio of reactant concentrations, which is known as the end point.
In a titration, a chemical indicator is chosen so that the equivalence point and the end point are the same.
This experiment is an acid–base titration. "the (previously unknown) concentration of an acid can be determined by titrating it
with a standard alkaline solution. The acid is neutralized by the alkali" (Lewis, R. & Evans, W., 2011).
Using a suitable indicator, which changed colour over an appropriate pH range at the end point, the end point of an acid–alkali
titration could be revealed. A different method of revealing the end point, which was the method that was constructed, is to
continuously monitor the pH value of the solution during the titration, carrying on until well past the end point. In this
experiment, there was a sudden swing in the pH value at the end point. The approximate

Investigating The Amount Of Calcium On The Calcium Oxide...
Discussion:
The purpose of this lab was to calculate the amount of calcium in Kirkland Signature's Calcium 600mg +D3 through the
processes of vacuum filtration and acid–base titration. These two methods were effective in determining the amount of calcium
in the calcium supplement with an error of +/– 0.05 g; the amount of calcium stated on the label was 600 mg. The reactions
that occurred during the process of vacuum filtration were:
CaCO3 (s) + 2HCl(aq) → CaCl2 (aq) +CO2 (g) + H2O(l)
CaCl2(aq) + Na2CO3(aq) → CaCO3(s) +2NaCl(aq)
The amounts of calcium calculated from the two trials of vacuum filtration were 0.554 g and 0.573 g respectively. The
calculations from the trials are shown in Equation 2 and Equation 3. The results from the vacuum filtration were very close to
the amount stated on the bottle. The small deviation from the original could be the result of inadequately removing all of the
ground powder from the mortar and pestle. This caused the original mass of the supplement to be less than what was expected,
hence the smaller final amount. There was a small difference in the procedures between the two trials of vacuum filtration.
During the second trial, more care and attention was given to make sure that the entire calcium supplement was transferred
from the mortar and pestle to the 250 mL Erlenmeyer flask. Because more care was given, the calculated amount of calcium
increased by 0.019 g.
The other method used in this lab was an acid–base titration. The

Essay On Titration Of Carbonate And Bicarbonate
Determine the total alkalinity of (=[HCO–3 +2[CO2–3]) by preforming a titration with the use of HCl.
Determine the Bicarbonate content (HCO–3 + OH– → CO2–3 + H2O) by preforming a titration with the use of NaOH to
convert HCO3– to CO2–3.
Calculate the composition of carbonate and bicarbonate in the solution.
Introduction
Acid–base titrations are common laboratory practices that are used to determine the concentration of either an acid or a base,
by neutralizing the substance with a known concentration of an acid or base. Crude sodium carbonate, also called soda ash, is
commonly used as a commercial neutralizing agent. In this experiment, we will determine the composition of an unknown
solid, knowing only that it contains sodium ... Show more content on Helpwriting.net ...
Using this, the concentration of carbonate can be determined from the total alkalinity (see Results).
Experimental Information
Procedure
At the start of the experiment all the following glassware was cleaned with DI water, and soap; then dried to remove traces of
DI water that remained. The glassware used was a 50mL buret, (3) 150 mL volumetric flask, a 25mL glass pipet, and a 250mL
volumetric flask. 2.5 grams of solid unknown was added to the 250mL volumetric flask with the use of a funnel, and DI water
was filled to the mark on the 250mL volumetric flask, making sure to rinse the funnel, so the unknown residue presented on the
funnel can rinse down into the flask. After removing the funnel, we diluted to the mark with DI water, and swirled the flask,
until all of the powder was dissolved. This experiment involved two different titrations. The first titration we observed was for
total alkalinity (=[HCO–3 +2[CO2–3]) which was measured by titrating the mixture with 0.1 M HCl to a bromocresol green
end point. After 2L of 0.1M HCl were prepared, and divided among all groups. 25.00–mL aliquot of unknown solution was
pipetted into a 150mL volumetric flask, using bromocresol green as the indicator, to observe the color change from a tinted
light blue to a tinted light green, being the

Cellular Respiration Lab Report
This experiment tested the hypothesis that there was no difference between cellular respiration before vigorous exercise and
cellular respiration after vigorous exercise in terms of rate of cellular respiration. During cellular respiration, glucose broke
down into carbon dioxide in order to convert the chemical energy stored in glucose into usable energy in ATP. Cells did not
perform cellular respiration to create carbon dioxide, for carbon dioxide was a byproduct, and thus, carbon dioxide was
released. In this experiment, the carbon dioxide was bubbled through water and, as a result, formed carbonic acid when carbon
dioxide and water reacted. Since acids donate hydrogen ions, carbonic acid––a weak acid––dissociated in water, which formed
... Show more content on Helpwriting.net ...
As soon as the stopwatch started, the subject blew into the straw until the solution appeared clear. When the solution appeared
clear, the stopwatch was stopped, and the time was recorded in a table as the subject's resting clearing time.
Next, a timer was set to five minutes, and the subject exited the lab room. As soon as the timer started to count down from five
minutes, the subject begun their exercise, which consisted of running laps around building on the second floor. When the timer
reached zero, the subject returned to the lab room and sat down in front of the second Erlenmeyer flask filled with prepared
solution that sat on top of a white piece of regular printer paper. The timer was set to zero, and then, as soon as the timer was
started, the subject blew into the straw until the solution appeared clear, which was when the stopwatch was stopped. Then, the
time was recorded as the subject's working clearing time. In the entire class, there were a total of twenty participants; the
twenty subjects consisted of both male and female students of varying ages and various races, including White and Hispanic
descent. We determined the class mean of resting and working clearing time, excluding four outliers.

Lipase Lab Report
The enzyme lipase, is present in one's body, specifically found in an individual's pancreas, mouth, and stomach. Lipase uses
separate fats to break down any consumed foods, so that they can proceed and be absorbed in the intestines. The body typically
produces lipase naturally but in some cases, people may need to use lipase supplements to assist them in digesting food. The
test to measure the lipase enzyme levels in your body is sometimes known as serum lipase. This test measures the amount of
lipase in your blood.
Lipase, like previously mentioned, is an enzyme found in your body. Because the average body temperature is Thirty–seven
degrees Celsius, the optimal temperature where this enzyme can work its best will most likely be around Thirty–seven

Sodium Hydroxide Reaction Lab
Experiment to investigate the amount of sodium hydroxide needed to neutralize the solution of vinegar
CH3COOH(aq) + NaOH(aq) –> CH3COONa(aq) + H2O(l)
(Reaction between sodium hydroxide and solution of vinegar, which produces an aqueous solution of sodium acetate and
water)
Hypothesis:
Approximately 8.8ml of sodium hydroxide will be required to neutralize 100ml of acetic acid.
(http://schoolworkhelper.net/titration–of–vinegar–lab–answers/)
–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––
Apparatus:
1. Burette 2. Funnel
3. Pipette 4. Phenolphthalein
5. Conical flask (100cm^3)
8. Solution of vinegar (0.5mol/L)
6. Clamp stand ... Show more content on Helpwriting.net ...
– Type of container (100cm3 of glass conical flask).
– Number of drops of phenolphthalein dropped in to the solution of vinegar.
– Temperature of the place where the experiment took place.
–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––
Method:
1. Measure 25ml of acetic acid and pour it inside the conical flask.
2. Place a burette on the conical flask and then hold it by using a clamp stand.
3. Measure 50ml of Sodium Hydroxide and pour in to the burette (use funnel, and remove after use).
4. Add 4 drops of phenolphthalein in to the prepared acetic acid, and check whether the color changes to dark pink.
5. Check whether it is ready or not, and then open the burette to start neutralize the acetic acid. (Check the progress by change
in colour)
6. When it is almost neutralized, pour possible minimum amount of sodium hydroxide for a fair result.
7. Repeat the same experiment several more times (at least 4) to calculate the average amount of sodium hydroxide, which is
required to neutralize the solution of vinegar.

Osmosis Lab Report
All proprieties of matter contain molecules that are either solids, liquids, or gases and carry factors of kinetic energy to do
work. These molecules move at a random but constant speed from areas of high concentration to low concentration in a solvent
through a semi–permeable membrane. This is called diffusion, and when cells diffuse water through a membrane it is called
osmosis. This creates a new solution when the chemicals within the solvent react to each other creating equilibrium between
the different molecules and their concentrations. In order to test this theory, we filled two different beakers, one with a 1%
concentration of sucrose and another with 10% concentration, and obtained 4 bags made of dialysis tubing. Dialysis tubing
works as a replica of a plasma membrane in the cell. Therefore, the results we see in our test corresponds to how a cell
membrane diffuses liquids in a solution. Our bags were filled with 10ml of sucrose at different concentrations; 1%, 10%, and
20%. We had two bags of the sucrose at a 1% concentration since we will be using it for both beakers in the experiment. A
dialysis bag that has a higher concentration of sucrose than the solution in the beaker would have to be losing its initial mass
throughout ... Show more content on Helpwriting.net ...
The water molecules bind to the chemicals added to create a contaminated water solution. The water molecules would still be
small enough to pass through the dialysis membrane, but combined with a chemical molecule of a large size prevents the
diffusion of the molecules from low to high concentration preventing equilibrium. Phenolphthalein is a pH indictor and will
turn red when reacting with a basic solution. Iodine is a starch indictor, and will react from its usual yellow color to a dark
blue/ black color. In order to test positive for any diffusion, a color change within the dialysis bags would have to

When Acetic Acid Meets The Criteria Of The Commercial Law
Introduction
In this experiment, you measure the acid concentration and determine if the acetic acid meets the criteria of the commercial
law. The titration of vinegar has a solution composed of acetic acid (HC2H3O2), water and other substances. When adding
sodium hydroxide (basic solution) to acetic acid (acid) it causes a neutralization reaction. The phenolphthalein is colorless in
acid, and it will change color when adding the sodium hydroxide. In this experiment, there were four trials to reach the amount
of sodium hydroxide needed to reach the end point. When you reach the end point of the experiment, the solution should be
pink and if the solution is purple then it is over titrated.
Discussion
First, you make sure all of the liquid (water) is emptied out of the buret. Next, you fill the buret with sodium hydroxide ...
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When pouring the NaOH in a flask, a drop of NaOH could be the difference of reaching the accurate measurement to titrate the
vinegar sample or you can over titrate the vinegar sample.
Questions
4. If the titrated standard NaOH, in the flask against vinegar, in the buret, instead of the way you actually performed the
titration, how would you have recognized the end–point with phenolphthalein indicator? Would carrying out the titration in this
manner change your calculated results or conclusions?
If the titration uses a phenolphthalein as an indicator, then its end point would always be recognized when the solution is pink.
5. Why is it a good idea to rinse the buret with the NaOH solution, instead of with water, before filling it at start of the
titration?
If you rinse the buret with water, there is still plenty of proton remaining and there shouldn't be any water left in the buret. If
so, NaOH solution would be less as stronger than presumed. You wouldn't get the accurate result because the solution would be
diluted. It would hard to determine the correct concentration of the

Diffusion And Osmosis
Why is diffusion and osmosis important and what were the reasons of the experiments performed? Osmosis helps keep the
water levels in cells at homeostasis and diffusion tries to reach equilibrium by moving to an area of lower concentration. The
two experiments were designed and performed to test the rate of diffusion by measuring the size of the phenolphthalein agar
block and the weight of the dialysis tubes. To begin with, the experiments, The Rate of Diffusion and Cell Size, was to test
whether the rate of diffusion was affected by the volume and surface area. It was hypothesized that the volume and surface area
of the phenolphthalein agar block and the dialysis tubing will have affect on the rate of diffusion. The first test was the
phenolphthalein–agar cube which was submerged into hydrochloric acid for a total of ten minutes along with other solutions
tested in the dialysis tubing. ... Show more content on Helpwriting.net ...
After analyzing the results of the data the rate of diffusion for the dialysis tubing and the block showed evidence of how a cell's
membrane functions. Nevertheless, after further examination I was able to determine that diffusion rate does depend on the
magnitude of volume or surface area. I learned that what caused the smaller 1–cm cube to become clear at a much faster rate
depended on the concentration of the hydrochloric acid. In other words if the proportion of the agar cube increased the
concentration of the hydrochloric acid got diluted and therefore became less effective. As a result, the agar cube was exposed
to the strongest concentration of acid therefore became clear at a faster rate. For future research it would be useful to measure
the concentration of the hydrochloric

Lab Report Acid Base Titration
Objective
The purpose of this lab was to perform acid base titrations using a pH electrode to monitor the equivalence point. Standardized
NaOH was titrated with HCl and acetic acid using phenolphthalein as the indicator. Each titration was analyzed by the
following plots to determine the equivalence point volume: pH vs volume, first and second derivative plot and Gran plot.
Methods
The pH meter and glass electrode were calibrated using buffers of pH 7 and 4. 25.00 mL of HCl solution was transferred using
volumetric pipet to a beaker containing 75.00 mL of water (N2 bubbled), stir bar and phenolphthalein. Initial pH of the solution
was recorded. After rinsing the buret and filling it with NaOH solution (made the first week), the acid was titrated by adding
NaOH in increments to get a 0.25 pH unit change. As the equivalence point approached, NaOH was added in increments of
half a drop to collect as many reading at the equivalence point. After equivalence point by 1.00 mL, NaOH was added in
increments of 1.00 mL until all of the solution was used. pH for each point was recorded after ~30 s of the addition. In between
changing the solutions, pH electrode was immersed in the buffer of pH 4.
The above procedure was repeated for acetic acid. Beaker containing 25.00 mL of acetic aicd,75.00 mL of water (N2 bubbled),
stir bar and phenolphthalein was titrated with the NaOH solution.
Discussion
The purpose of this experiment was to determine the equivalence point of the two reactions:

Macroscopic Evidence Of A Chemical Reaction Lab Report
1. What type of macroscopic evidence for chemical change did you observe during this experiment? Give at least three
different examples. (15 points) The main evidence of chemical change in this lab is the change in color, production of gas, and
the production of precipitate. These reactions can be seen from just a little bit of reaction all the way up to a complete change
of the entire sample tested. Some samples of those tested in this experiment which showed the chemical reaction were the
baking soda/ammonia mixture, the Epson salt and baking soda mixture as well as the food coloring mixed with the baking soda
and bleach. 2. Which reactions, if any, do you believe showed no evidence of chemical change? Justify your reasoning. (15
points) There was one combination that did not have any reaction when tested. This combination was the MgSO4 and
CH3COOH. The reason that the reaction did not happen is because they created a mixture and not a chemical change. 3. ...
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When two solutions combine and a solid substance is formed, this solid is called a precipitate. In your experiments, if the clear
reactant solutions you combined together formed a cloudy product, then a precipitate (solid substance) was formed. Describe
the precipitates (according to color and clarity) and the substances that formed them. (18 points) The combinations that formed
precipitates in my experiment were MgSO4 and NH3, MgSO4 and Na2CO3, Na2CO3 and CH3COOH. The two most obvious
formation of the precipitate were the combinations with the MgSO4. The MgSO4 and NH3 solution became very opaque and
the MgSO4 and Na2CO3 turned from liquid to a full solid white substance. The Na2CO3 and CH3COOH did not have as
strong of a reaction, however, the precipitates were able to be visualized with in the clear

Lab Report Acid Base Titration
Title: ACID BASE TITRATION. Objectives: 1. To determine the concentration of acid using titration. 2. Skills of titration
techniques. Apparatus: 1. 250 volumetric flask 2. 10mL measuring cylinder 3. 25mL pipette 4. 50mL burette 5. 250mL beaker
6. 150mL conical flask 7. Retord stand 8. White tile 9. Stopwatch 10. Pipette bulb Chemicals: 1. HCl solution 2. 0.1M NaOH
solution 3. H2SO4 solution 4. Distilled water 5. phenolphthalein Introduction. An acid–base titration is the determination of the
concentration of an acid or base by exactly neutralizing the acid/base with an acid or base of known concentration. This allows
for quantitative analysis of the concentration of an unknown acid ... Show more content on Helpwriting.net ...
For H2SO4: 2 mole of NaOH reacted with 1 mole of H2SO4. 2) Why are HCl and H2SO4 known as strong acid? * Because
they reacted 100%. 3) Give one example of a weak acid and explain why it called a weak acid. * Ethanoic acid, when it
reacted, it do not dissolves 100%. * It only dissolve 4% and tend to return to its original state. Conclusion. ACID–

3 Agar Cubes Containing Ph-Indicator Dye Phenolphthalein
Start the experiment by taking 3 agar cubes containing pH–indicator dye phenolphthalein, and have the teacher cut three
different cubes each with different measures; a cube measured 3cmx3cmx3cm, another 2cmx2cmx2cm, and another
1cmx1cmx1cm. (The agar cubes are acting as artificial cells for this experiment). Place each agar cube in the solution of
vinegar and water, and start the stopwatch as soon as the cubes hit the water. Stop the stopwatch as soon as the smallest cube
becomes fully clear and record how much time it took for the physical property to completely change. The agar cube is
supposed to change color from pink to white, the phenolphthalein dye gives the agar cube the pink color. The purpose of this
experiment is to test the relationship

Essay about Lab Observations of Chemical Changes
Purpose: The purpose of this experiment is to observe chemical changes in common consumer products to determine if the
chemicals are basic, acidic, or remain neutral when mixed with other chemicals.
Procedure: In this experiment, various chemicals were mixed together, to determine a reaction. Using two drops from chemical
1 and two drops of chemical two, unless otherwise stated, then recording the type of physical reaction or color changes that
occurred.
Well#/questions Chemicals Reactions
A NaHCO
3
and HCI – C0
2
When combined Sodium Bicarbonate and Hydrochloric Acid, Carbon Dioxide is produced. The two chemicals do not undergo
a change in color but a chemical change when CO2 is produced. ... Show more content on Helpwriting.net ...
Meaning the combination produces a base.
Questions:
1.) Suppose a household product label says it contains NaHCO3. How would you test this material for the presence of sodium
bicarbonate?
a. Add hydrochloric acid to the household product, and if the chemicals began to bubble, once mixed together, then this would
indicate that sodium bicarbonate is present.
2.) You know what color phenolphthalein and BTB turn when testing an acid or a base. Use three household cleaning products
with BTB. Name the items tested and their results:
a. Windex: when combined with BTB this cleaner changed orange, indicating that the cleaner has an acidic ph.
b. Fabuloso: When combined with BTB this cleanser changed to light blue, indicating that this cleaner is basic.
c. Bleach: when combined with BTB this cleaner changed orange, indicating that the cleaner has an acidic ph.
3.) You find a sample of a solution that has a faint odor resembling vinegar. You are verifying that it is indeed vinegar and you
add a few drops of phenolphthalein. The sample turns pink. What assumptions can you make about this sample?
a. Vinegar is a common household product, when mixed with the indicator, phenolphthalein, it turns pink. This indicates that
Vinegar is acidic.
4.) You want to investigate a new wave of vitamin water is pH neutral. Results are: Three of the five samples turn a murky

Acid-Base Titration Lab
Abstract
By using acid–base titration, we determined the suitability of phenolphthalein and methyl red as acid base indicators. We found
that the equivalence point of the titration of hydrochloric acid with sodium hydroxide was not within the ph range of
phenolphthalein's color range. The titration of acetic acid with sodium hydroxide resulted in an equivalence point out of the
range of methyl red. And the titration of ammonia with hydrochloric acid had an equivalence point that was also out of the
range of phenolphthalein.. The methyl red indicator and the phenolphthalein indicator were unsuitable because their pH ranges
for their color changes did not cover the equivalence points of the trials in which they were used. However, the ... Show more
content on Helpwriting.net ...
Results
Part I: Data and Calculations
Table 2: Titration Data Table
Trial 1 – HCl and NaOH (Strong–Acid + Strong–Base)
Trial 2 – CH3COOH and NaOH (Weak–Acid + Strong–Base)
Trial 3 – NH3 and HCl (Weak–Base + Strong–Acid)
(*) marks equivalence range
Trial 1Trial 2Trial 3
Titrant Volume (mL)
pHTitrant Volume (mL)pHTitrant Volume (mL)pH
0.001.70.003.10.0010.4
5.001.75.004.05.009.7
10.001.710.004.410.009.3
15.001.815.004.815.008.9
20.002.020.005.120.007.9*
21.002.121.005.321.006.0
22.002.122.005.421.503.8
23.002.223.005.522.003.1
24.002.224.005.722.502.9

25.002.325.006.2*23.002.7
26.002.425.506.723.502.6*
27.002.726.009.824.002.5
28.003.026.5010.524.502.4
29.003.3*27.0011.2*25.002.4
30.003.827.5011.426.002.3
30.509.428.0011.627.002.2
31.0010.3*29.0011.728.002.2
31.5010.830.0011.830.002.1
32.0011.031.0011.835.002.0
33.0011.232.0011.840.001.9
35.0011.534.0011.9
40.0011.835.0011.9
40.0012.0
Table 3: Equivalence Point values.
Equivalence Point
Titration of HCl with NaOH7.0
Titration of CH3COOH with NaOH8.6
Titration of NH3 with HCl 5.5
1)Initial pH
See Table 2.
2)Final pH
See Table 2.
3)Equivalence Range
Using Graph 1: The Volume of Titrant Added in order to reach the Endpoint and the Corresponding pH Values, observe the
vertical line of each titration and see the points in which the horizontal lines intersect it. These points give the

Limewater Test Lab Report
1. Limewater Test: As we exhaled CO2 in the limewater solution, the CO2 reacted with Ca(OH)2 and changed the clear
colorless limewater solution to precipitated white solution. The precipitation was caused due to the calcium in the limewater
solution. It took us 5 attempts to turn the clear colorless limewater solution to a milky white solution. 2. Phenolphthalein
Indicator Test: As phenolphthalein indicator was added to NaOH and H2O solution, it made the solution turn clear pink. The
phenolphthalein indicator detects the presence of the base in the solution by changing the color of the solution from clear
colorless to clear pink. As we exhaled into the pink solution, the CO2 reacted with the NaOH and H2O solution. This makes
the solution ... Show more content on Helpwriting.net ...
Phenolphthalein Indicator Test: CO2 (g) + H2O(l) ––> H2CO3(aq) H2CO3(aq) + 2NaOH(aq) ––> Na2CO3(aq) + 2H2O(l)
How would the results of both tests be affected if you performed the tests immediately after vigorously exercising for several
minutes? Explain. Performing vigorous exercise requires a high demand of energy in order to be accomplished, the body
adapts to this change by increasing the rate of aerobic cellular respiration which would produce more energy to meet the needs.
As a result there would be much more carbon dioxide being exhaled from the body as it is one of the waste products produced
during aerobic cellular respiration. CO2 is specifically formed during the Pyruvate oxidation and Kreb Cycle stage of the
cellular respiration. To exemplify during pyruvate oxidation one of the steps is a decarboxylation reaction in which the
carboxyl group of pyruvate is removed to from CO2. Overall for one glucose molecule two molecules of CO2 is released
during pyruvate oxidation as glycolysis yields two pyruvate molecules. Furthermore the Krebs Cycle also produces CO2
molecules during the oxidation of isocitrate which produces a–ketoglutarate. Another CO2 molecule is also produced during
the oxidation of a–ketoglutarate. This reaction produces the molecule succinyl CoA. As a result two CO2 molecules are
produced for one acetyl–CoA. These points exemplify how the increase rate of cellular respiration would increase the rate of
CO2 being exhaled. In connection to the lab investigation this would speed up the rate of reactions as there would be a much
higher concentration of CO2 being exhaled compared to when the body is at rest. As a result this would increase the amount of
product being produced because of the increase of CO2 in the reaction. Due to which the lab experiment would occur at a
higher rate and it would be faster as

Quantitative Analysis of Soda Ash by Double Indicator Method
Quantitative Analysis of Soda Ash by Double–Indicator Method
Mark Steven R. Santiago and Kristiene B. Sadiwa Institute of Chemistry, University of the Philippines, Diliman, Quezon City
1101 Philippines Date/s Performed: July 13, 2012; Date Submitted: July 19, 2012 Results and Discussions A mixture of
carbonate (CO32–), bicarbonate, (HCO32–) and hydroxide (OH–) ions can be analysed and determined by titration with strong
standard acid solution. Volumetric titrimetry can be employed to compute percent compositions of sodium carbonate
(Na2CO3), sodium bicarbonate (NaHCO3), and sodium hydroxide (NaOH) in a soda ash sample through the application of
neutralization concepts and titrimetric analyses. Volumetric titrimetry has been utilized in ... Show more content on
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Moreover, NaOH cannot replace Na2CO3 for it generally do not satisfy above requirements and very hygroscopic in nature.
On the other hand, 0.05 M HCl is called the standard solution. An ideal standard solution[3] is (1) sufficiently stable to
determine concentration, (2) reactive with the analyte so that the time required between additions of titrant is minimized, (3)
completely reactive with the analyte so that satisfactorily end points are realized, and (4) selectively reactive with the analyte
that can be described by a simple balanced equation. The standardization of the titrant aims to know the exact concentration of
the titrant (its deviation from the measurement done). Two basic methods are used to establish the concentration of standard
solutions: (1) direct method, in which a carefully weighed quantity of a primary standard is dissolved and diluted to an exactly
known volume in a volumetric flask, and (2) standardization by titrating (a) weighed quantity of a primary standard, or (b) a
measured volume of another standard solution. In the
experiment, the standard solution has been standardized using method 2b[3]. The standard solutions

Cellular Respiration Experiment

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Cellular Respiration Experiment