Sing A Primary Standard To Analyze Acid And Base Solutions

sing a primary standard to analyze acid and base solutions
Using a primary standard to analyze acid and base solutions Acid–base titration Lab 13G
Jake Shewchuk Lab 13C Dominique Genereux
Purpose 13G:
1. To prepare a standard solution of oxalic acid and use it to standardize an unknown sodium
hydroxide solution.
Purpose 13C:
1. To titrate a hydrochloric acid solution of "unknown" concentration with standardized 0.5M
sodium hydroxide.
2. To titrate a hydrochloric acid solution of "known" concentration with standardized 0.5M sodium
hydroxide.
3. To titrate an acetic acid solution (vinegar) with standardized 0.5M sodium hydroxide.
4. To utilize the titration results to calculate the molarity of the hydrochloric acid and the ... Show
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% difference= (larger value – smaller value)/ (larger value + smaller value)/2 * 100%
% difference= (.5418M – .5225M)/ (.5418M+ .5225M)/2 * 100%
% difference=.91%
Follow up 13G:
1. The property of this acid solution (soft drink) overcome by using of sugar or artificial sweetener
is the sourness. Most acids are sour so the sugar makes it sweeter in a soft drink, so it is more
desirable to drink.
2. What mass concentrated HCl will be required required to neutralize the NaOH? NaOH moles
n=C*v n=8.0x103L* .040M n=320 mols HCl moles =320 mols HCl volume v=n/C v=320 mols /
12M v=26.66666 HCl mass m=d*v m=1.2Kg/L / 26.66666 m=32Kg or 32000 g 3. Calculating the
the percentage by mass of NaCO in the sample:
Moles of HCl n=C*v n=.500M*.0486L n=.0243mols Moles of NaOH n=m/MM n=1.00g/40.0
n=.0250mols 2HCl(aq) + Na2CO3 → 2NaCl(aq) + H2O(l) + CO2(g)
Moles of Na2CO3 n=m/MM n=1.00g/160.0 n= .0094339623moles .0243 (moles of HCl) = x *
0.01887 + (1.000 – x) * .0250 .0243 = .01887x + .0250 – .0250x
.00613x = .0007 x=0.114 Percentage of Na2CO3 by mass is 11%
4. It would be difficult to measure the concentration of acid in red wine or coca–cola because the
colour of the drink is too dark for us to see when the phenolphthalein indicator changes colour. You
could overcome this difficulty by using a pH meter.

5. Explaining why the conductivity reaches a minimum.
Ionic equation:
Ba2+(aq) + 2OH–(aq) + H+(aq)+ HSO4(aq) → BaSO4(s) + 2HOH(l)
At the neutralization
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Investigating The Concentration Of A Hydrochloric Acid A...
The objective of the lab was to prepare standardize solution (titrant: NaOH) of sodium hydroxide,
and to determine the concentration of a hydrochloric acid and KHP solution using acid‐base
titration. Standardization is the process of determining the exact concentration (molarity) of a
solution. The molarity (M) of a solution is used to represent the amount of moles of solute per liter
of the solution. Titration is one type of procedure often used in standardization process. A titration is
a technique where a solution of known concentration is used to determine the concentration of an
unknown solution.
In a titration, an exact volume of one substance(NaOH) was reacted with a known amount of
another substance (HCl). The point at which the reaction was complete in a titration is referred to as
the endpoint. We recognized a solution which reached the endpoint: when we saw a solution
completely turned into pink color. A chemical substance known as an indicator was used to indicate
the endpoint. An indicator is a substance that undergoes a distinct observable change (pink color)
when conditions in its solution change. The indicator we used in this experiment was
phenolphthalein because Phenolphthalein is a weak acid. The weak acid is colourless and its ion is
bright pink. And the solution turned pink when we added a basic solution (NaOH) into the solution
because adding hydroxide ions removes the hydrogen ions from the equilibrium which replace them
turning the indicator

Detection of Ions in Solutions Using Acid/Base Chemistry:...
Detection of Ions in Solutions Using Acid/Base Chemistry: A Quality Control Test
Objective: This lab focuses on the detection of ions using titration as an analysis tool. You will
standardize NaOH and HCl solutions so that you know the exact concentration and then prepare
samples of common household items in order to determine the amount of calcium in Tang®,
Mg(OH)2 in Milk of Magnesia, etc. You will learn to prepare samples of a specified concentration,
learn about acids and bases through the use of titrations and learn how to detect endpoints using
different indicators. You will become adept at measuring pH with both a pH meter and indicator
paper. You will then conduct quality control testers and determine if the label on a ... Show more
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To calibrate the pH meter:
1. Remove the electrode from the distilled water and place it in pH 4 buffer, which is pink. Make
sure the electrode is completely covered in buffer and swirl the solution around.
2. Set the pH meter to pH 4 and then rinse the electrode with distilled water to remove any excess
solution.
3. Place the electrode in pH 10 buffer (which is blue) and swirl it around in the solution.
4. Set the pH meter to pH 10 and rinse the electrode, returning it to the distilled water once you are
finished.
The pH meter should now be calibrated to measure any pH accurately.
Standardizing a Sodium Hydroxide (NaOH) Solution
In a titration, it is critical to know the exact concentration of the titrant (the solution in the buret
which will be added to the unknown) in order to determine the concentration of the solution being
tested. We will standardize the ~0.1 M NaOH solution (the titrant) with potassium hydrogen
phthalate (KHP, KC8H4O4H) using phenolphthalein as the indicator. KHP is a weak acid and reacts
with base in the following way:
To Standardize:
1. Weigh ~0.8 g of dried KHP (MW = 204.23 g/mol) into an Erlenmeyer flask and dissolve in 50–75
mL of distilled water. Record the amount of KHP and water used.

2. Add 4 drops of indicator into the flask and titrate to the first permanent appearance of pink. Near
the endpoint, add the NaOH dropwise to

Advantages And Disadvantages Of Hydrocolubic Solubility
HYDROTROPIC SOLUBILIZATION [23][24] [25][26] Use of Additives may increase or decrease
the solubility of a solute in a given solvent. The effect of an additive depends very much on the
influence: it has on the structure of water or its ability to compete with solvent of water molecules. A
convenient quantitation result of the solute additive on the solubility of another solute may be
obtained by Setschenowequation.
Log S0/S = KCa where S = solubility in the presence of additive
Ca = additive concentration
S0 = solubility in the absence of additive
K = salting coefficient,
It is a measure o the sensitive action of the coefficient solute towards the salt. Various salts through
large anions or cations which are themselves very ... Show more content on Helpwriting.net ...
3.4 ADVANTAGES OF MIXED HYDROTROPIC SOLUBILISATION The advantages of mixed
hydrotropic solubilisation are as similar to hydrotropic solubilisation. One more advantage is that to
reduce the concentration of individual hydrotropic agent and minimize their toxicity of individual
hydrotropic agent.
3.5 MIXED SOLVENCY [31][32][33] Maheshwarihave proposed the concept of mixed solvency.
His opinion is that all substances whether liquids, gases or solids is solubilizing powder and hence
concentrated aqueous solution containing various dissolved substances can also improve the
solubility of poorly water soluble drugs. Melted (temperature less than 100 ºC), PEG 400, PEG 6000
and PEG 8000 dissolves diclofenac sodium (melting point: 283 ºC). This also shows that melted
PEGs act as solvent for diclofenac sodium. Melted urea (M.P.: 132–135 ºC) dissolves diclofenac
sodium (M.P.: 283ºC). This shows that melted urea act as solvent for diclofenac sodium. Melted
ibuprofen (M.P.:78ºC) dissolves diclofenac sodium (M.P.:283ºC), salicylic acid (M.P.:159ºC) and
niacinamide(M.P.:132ºC), which another time shows that melted ibuprofen act as solvent for
diclofenac sodium, salicylic acid and niacinamide respectively.In supercritical fluid technology

Anthracene Solubility
The experiment contains two procedures: the solubility tests, and macroscale recrystallization of
chosen solutes and solvent. The solubility tests were performed with all the solutes, which were
phthalic acid, naphthalene, anthracene, benzoic acid, and resorcinol. The three solvents were water,
methanol, and acetic acid. Solubility tests were carried out at both low and high temperature
conditions, depending on the substance. The most efficient pair was acetic acid and anthracene,
which was chosen for the second part of the experiment. In the macroscale procedure, 47.57% of
anthracene was recovered. The crystals had a powdery physical appearance. There were several
errors in the experiment, such as loss of solids due to unnecessary transfer, ... Show more content on
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A solute and solvent were chosen from the list to start with. Around 10 mg of solid and 0.25 mL of
solvent were added to a clean reaction tube. A pipette was useful in transferring the solvent to the
tube. The mixture was stirred with a glass stirring rod. If the substance was completely dissolved at
room temperature, a few drops of water would then be added to see if the solid precipitated. If so,
the solution would be heated to boiling point in a sand bath. The hot saturated solution was left
undisturbed for a period of time, before the crystals formed. In case that the substance could not
dissolve at room temperature, it would have to be heated and further observed. If the solid dissolved
entirely, the substance was considered soluble in the hot solvent. On the other hand, if some but not
all dissolved, it was noted as moderately soluble. Continually, the solution was allow to cool down,
before it was reheated to dissolve the solid. The solution stood undisturbed until crystals were
formed. Solubility tests were performed on all possible solvent–solute pairings. The most efficient
pair was

Molar Concentration Lab Report
Introduction:
In 1909 S.P.L. Sorensen published a paper in Biochem Z in which he discussed the effect of H1+
ions on the activity of enzymes. In the paper he invented the term pH to describe this effect and
defined it as the –log[H1+ ]. In 1924 Sorensen realized that the pH of a solution is a function of the
"activity" of the H1+ ion not the concentration and published a second paper on the
subject. A better definition would be pH=–log[aH1+ ], where aH1+ denotes the activity of the H1+
ion. The activity of an ion is a function of many variables of which concentration is one. It is
unfortunate that chemistry texts use a definition for pH that has been obsolete for over 50 years.
Because of the difficulty in accurately measuring ... Show more content on Helpwriting.net ...
Keyterms:
Buffer: a substance or combination of substanes capable of neutralizing limited quantities of either
acid(H3O+) or base (OH–) added to it.
Dynamic Equilibrium: Two offsetting processes occur at equal rates, producing a state of balance
where no net changes is observed.
Molar Consentration or Molarity: Concentration of a solution measured as the number of moles of
solute per liter of solution. For example, a 6 M HCl solution contains 6 moles of HCl per liter of
solution.
Hypothesis:
I predict that out of the 20 solutions that we are going to be testing, about 6 of them will be an acid,
3 will be neutral and 11 will be a base.
Data Table:
UNKNOWN Acid or
Base pH
1 Neutral 6
2 Neutral 7
3 Base 8
4 Acid 3
5 Acid 4
6 Acid 3

Unknown Permanganate Solution Lab Report
In this experiment, the concentration of an unknown permanganate solution will be determined.
Spectroscopic techniques will be used to measure various known concentrations of permanganate
solutions to create a calibration curve for the absorbance of light vs. the concentration and will be
used to determine the unknown concentration1.
Introduction
In order to perform this experiment, proficiency with using spectrometers, burettes, volumetric
flasks, weighing by difference, and making a hot–water bath are essential1.
By using a spectrometer's function to analyze the absorbance of light of each of the known
solutions, the resulting linear correlation will provide an equation similar to the Beer's Law equation
required for calculations1.
The linear ... Show more content on Helpwriting.net ...
Procedure
1. Obtained required materials and prepared necessary setup to complete the experiment.
2. Prepared unknown solution by using a hot–water bath to heat the 100mL volumetric flask
containing 35mL of the unknown Mn2+ solution, 5mL of the provided phosphoric acid and between
0.3 to 0.5g of potassium periodate1.
3. While the unknown solution was being made, five cuvettes were prepared, one containing
distilled water to calibrate the spectrometer and the other four, separately containing one of the four
known permanganate solutions1.
4. After calibration, the most concentrated (known) solution was used to obtain max. The
significance of this step is to set the spectrometer to measure at that particular wavelength1.
5. Manipulated with settings on the program to display a graph showing absorbance vs.
concentration. Collected absorbance data for the three remaining known solutions to obtain a linear
fit1.
6. Returned to the unknown cooked solution and collected absorbance data for the solution using a
cuvette. Recorded results and used mathematics to ultimately determine the concentration of the
unknown

Egg Osmosis Lab Report
Introduction:
Osmosis is the movement of water from a less concentrated solution to a more concentrated solution
through a semipermeable membrane because it is active transport, thus going against the
concentration gradient.1 This process was initially thoroughly studied 1877 by German plant
physiologist, Wilhelm Pfeffer.2. For Osmosis to occur, it requires two solutions with different
concentrations and a partially permeable membrane to separate them. Since the water diffuses
towards the more concentrated side of the membrane, the concentration of the more concentrated
side will continue to rise, which while the one on the less concentrated side falls. However if the
concentration of both sides of the semi–permeable membrane are equal in ... Show more content on
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When the egg was submerged in the 5% NaCl for 10 minutes, it continued to gain mass and not lose
mass, therefore indicating that the conditions were still hypotonic. The conditions began to be
hypertonic when the egg was submerged in the 10% NaCl solution. While the egg was also in the
10% NaCl solution, the conditions became isotonic within those 10 minutes, indicating that the
intracellular conditions and the extracellular conditions of the egg were at equilibrium. However it is
unknown at exactly what time or how long the conditions remained at equilibrium. The graph Figure
7, illustrates this when the line of best fit creates an x–intercept indicating that the rate of osmosis
was 0g.m–1. However osmosis could have still occurred, but was not detected due to no change in
mass. When the mass of the egg increases, it indicates that more water is flowing into it due to the
internal environment of the egg being of higher concentration to the external environment.
Alternately, when the egg loses mass, it indicates that water left the egg into the external
environment because the external environment would have had a higher salt (NaCl)

Recrystallization Of Naphthalene Lab Report
Recrystallization of Pure Phthalic Acid, Benzoic Acid and Naphthalene
Laboratory Partners:
TA:
September 27, 2016 Introduction
Recrystallization is a process used to purify compounds that form a crystal lattice from a
supersaturated solution. The crystal lattice will not contain the impurities present in the crude
sample. Activated charcoal is used as an adsorbent for the heavier impurities that discolor the
compound. Since no one solvent is a perfect choice for recrystallization, sometimes two solvents are
used as a solvent pair in a recrystallization.
Experimental Section
Part 2: Recrystallization of Benzoic Acid
Part 3: Recrystallization of Naphthalene Table of Chemicals
Name Molecular Formula Structure Molar Mass
(g/mol) Melting ... Show more content on Helpwriting.net ...
Experimental Melting Points and Percent Recovery from Recrystallization
Compound Melting Point (°C) Mass Collected (g) Percent Recovery
Phthalic Acid 208 0.0025 1.25%
Benzoic Acid (Method 1) – – –
Benzoic Acid
(Method 2) – – –
Naphthalene 78 0.709 70.9%
Percent Recovery=(Pure Product Recovered)/(Crude Material)×100
Phthalic Acid =(0.0025 g)/(0.200 g)×100=1.25%
Naphthalene =(0.709 g)/(1.00 g)×100=70.9%
Discussion
The melting points of the compounds obtained through recrystallization were determined and
comparing them to the literature values for their melting points determined the purity of the
compounds obtained. The melting point obtained for phthalic acid, 208 °C, was very similar to the
literature melting point for phthalic acid, 210 °C. The literature values for phthalic acid are very
variable however, so the small variation from the literature value does not indicate that the phthalic
acid was impure. No melting points were measured for benzoic acid. The first method for
recrystallization of benzoic acid produced some precipitate, but all of it drained into the vacuum

flask during the vacuum filtration. The second method for recrystallization of benzoic acid failed to
produce any precipitate; failure of the solution to become cloudy while adding water resulted in an
excess of water being added to the solution, reducing the saturation of the solution.

Egg Osmosis Lab Report
INTRODUCTION My Definition of Osmosis is the Diffusion of fluid through a semipermeable
membrane from a solution with a low solute concentration to a solution with a higher solute
concentration until there is an equal concentration of fluid on both sides of the membrane. Sucrose
is very dense and comes from a high concentration of dissolved sugar. These sugar molecules are
too large to pass through the semipermeable membrane of the egg, but the water molecules from the
egg will. When these water molecules pass through the membrane of the egg into the sucrose until
the concentration of water molecules are the same on both sides. The water movement, from egg to
syrup, results in Osmosis.
HYPOTHESIS
My hypothesis is that the concentration ... Show more content on Helpwriting.net ...
Looking at the graph, Egg two in group two would only be the example of this occurrence.
Explanation of Findings in Graphs and Tables 1–7 After analyzing the data, it seems to me that the
less sucrose in the solute, the higher the volume of solute the membrane ingests. In the case of the
hypertonic solution, there were more solutes in the corn syrup than there were in the egg. In the case
of the isotonic solution, there was roughly an equal number of solutes in the corn syrup/water
solution than there was in the egg, so there was no movement in or out of the egg. It stayed the same
size. In the case of the hypotonic solution, there were more solutes in the egg than in the pure water.
So, water flowed into the egg, and as a result, it grew.

Nitrophenol Lab
Method The first portion of the lab was about preparing the standard curve for the reaction products.
In this part we already know the concentration of the product, Nitrophenol. So, to perform this we
took six test–tubes and filled each with 1ml of standard labeled with S1–S6 respectively. For
example 1st =S1, 2nd=S2, 3rd =S3 and so on. After that we measured the absorbance of each test
tubes setting the first one as blank. And the data is recorded in the table (5.1). After recording the
reading we constructed a Nitrophenol Standard curve by plotting A410 on y–axis and concentration
on the x–axis as on figure (5.2). The second portion require us to prepare acid phosphatase from the
wheat germ extract. But, this part of the lab was already ... Show more content on Helpwriting.net ...
With respect to the time mentioned on the laboratory paper we transfer 0.5ml of the solution from
the solution from A to (A1–A6) and B to (B1–B2). After doing that we simultaneously measured the
absorbance using the photo spectrophotometer. The reading are recorded in the table (5.3) and with
the help of this readings we plotted graph which is shown in the figure (5.4). The fourth step of the
experiment was to determine the Vmax and Km for the acid phosphatase. In this part we first look at
the graph from part three of this experiment which is the nitro–phenol standard curve which is on
the figure (5.2). And have chosen the points which were falling on the trend line (slope). After that
we took seven test–tubes and added 1ml of substrate which was already prepared by the instructor in
each of the seven test–tubes. And to that we added 50µL of purified acid phosphatase (125µg) to
each tube at 30 second intervals to stop the reaction. After the end of 2.5min, we added 1.5% (w/v)
KOH to each test tubes at 30 seconds intervals to stop the reaction. After completing this step we
used nitro–phenol standard curve to quantify the concentration nitro–phenol produced

Ap Biology Egg Osmosis Lab Essay
AP Biology
August 23, 2012
Egg Osmosis Lab
Definition of osmosis: The diffusion of water across a selectively permeable membrane from high to
low concentrations
Hypothesis: If I place an egg in vinegar, then the outer layer of the egg is going to become slimy and
look like rubber. It will also become larger and bubbles will form on and around the egg.
Hypothesis: If I place an egg in corn syrup, then the egg will become small and the outer layer will
not look like rubber any longer.
Day one:
Date started: 8/6
Volume: 2 oz. pH of acetic acid: 2.4
Day two
The egg shell completely disappears due to the vinegar reacting with the egg; bubbles form on the
surface of the vinegar and on the egg because carbon dioxide was produced from ... Show more
This is also known as a hypertonic solution which explains why the egg will decrease in size. Corn
syrup is a hypertonic liquid because it is very concentrated with not much water compared to the
egg unlike water which is hypotonic because it contains more water than the egg. In this solution,
the solute remains the egg, and the solvent is changed to corn syrup. Osmosis still plays an action
because water is still passing through the membrane from high to low concentrations.
Hypothesis: If the egg is placed into water, then it will increase in size since water is a hypotonic
liquid because it contains more water than the egg.
Day Five
Egg volume: 4oz.
Remaining water: 6oz.
Conclusion:
Osmosis took place in the egg under a variety of conditions because the membrane of the egg has
tiny openings where water can pass through from high to low concentrations. On day one, it was a
hypotonic solution because the higher concentration of water in the vinegar moved to the smaller
concentration in the egg. This means the egg was filled with water, which resulted in the eggs
increase in size. On day three, the hypotonic solution occurred because the corn syrup had a lower
concentration of water than the egg. That means the egg released water into the corn syrup, which
resulted in the eggs decrease in size. On day four, the egg was placed in water which resulted in an
isotonic solution where the concentrations become even. This

Freezing Point Depression Lab Report
Introduction
Molar mass is a fundamental quantity of chemistry. There are multiple ways to find the molar mass
of a substance experimentally; one way is to use Freezing Point Depression by using the following
equation: ΔT= kf*m (Robinson, 2018). The purpose of this lab was to do just that; measure the
freezing point depression of a solution when a solute is added to a solvent, and from that, determine
the molar mass of an unknown substance, along with learning about the influence that solutes have
on liquid properties. A concept of importance to this experiment is freezing point. According to
LibreTexts, "Freezing point depression is a colligative property observed in solutions that results
from the introduction of solute molecules to a solvent...and ... Show more content on
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Colligative properties, such as boiling point and freezing point, are dependent on the amount of
solutes added, not necessarily their identities (LibreTexts, 2018). A fascinating concept related to
freezing points is Supercooling. Supercooling is a state where liquids do not form ice even when
they reach temperatures below their normal freezing point; they are trapped in a metastable state
(Esrf.eu, 2018). The best example of this is clouds at high altitudes: they contain tiny droplets of
water that do not have seed crystals, and therefore do not form ice despite the low temperatures
(Esrf.eu, 2018). The concept of freezing point depression is applicable in many parts of everyday
life. The most common example of freezing point depression is in the salting of roads when it snows
(Kimbrough, 2006). As the melting of the first flakes on the warm road occurs, a solution of salty
water is created which has a lower freezing point than pure snow (Kimbrough, 2006). Now, the
temperature will not get cold enough to freeze the salty solution the way it can freeze water, keeping
ice and snow from bonding to the pavement (Kimbrough, 2006). In this lab, the freezing point
depression was calculated experimentally by adding an unknown solute to Lauric Acid,

Using Colorimetry To Determine The Concentration Of Copper...
Introduction: The goal of this lab was to use the technique of colorimetry to determine the
concentration of the Cupper (II) ion, Cu2+, in a sample of ore. Then a colorimeter or
spectrophotometer probe was used to determine the relationship between concentration and light
absorbance Using the known solutions of Cu2+concentrations. Points were then graphed which
allowed determination of the concentration of the solution with unknown Cu2+concentration from
its absorbance measurement. A standard curves shows the relationship between two variables. In this
investigation the two variables that were showing a relationship were absorbance and concentration.
Which are used in the beer lambert law. A=bC A standard curve was used to represent the
relationship between the absorbance and concentration from that equation. Ten different dilutions
were formed. From those dilutions the concentration and absorbance was determined. Then these
values were plotted. Absorbance was plotted on the y–axis and concentration was plotted on the x–
axis. A straight line was formed.
Procedure:
This experiment took place during two lab sessions over two weeks. Part 1 of the experiment was to
determine the equation ... Show more content on Helpwriting.net ...
To make the standard solution, 1 gram of the solid Copper Nitrate was massed using an electric
scale, and added to a 100mL beaker. 20mL of H2O was then added to the beaker. A blue color was
produced due to the dissolving of the Copper Nitrate in the water. To enhance the color of the
standard solution to be readable in the colorimeter, 20mL of Ammonium Hydroxide (NH4OH) was
added. The color of the standard solution became a very deep blue color. To find the concentration
of the standard solution, the volume of the standard solution was divided by the calculated moles of
the Copper Nitrate and

Osmosis Lab Report
osmosis diffusion of water across a selectively permeable membrane depending on the concentration
of solutes on either side of the membrane
isotonic solution in cells, a solution in which the concentration of dissolved substances in the
solution is the same as the concentration of dissolved substances inside a cell
hypertonic solution in cells, a solution in which the concentration of dissolved substances outside
the cell is higher than the concentration inside the cell; causes a cell to shrink as water leaves the
cell
hypotonic solution in cells, a solution in which the concentration of dissolved substances is lower in
the solution outside the cell than the concentration inside the cell; causes the cell to swell and
possibly burst as water ... Show more content on Helpwriting.net ...
phase of photosynthesis where light energy is converted to chemical energy in the form of ATP;
results in the splitting of water and the release of oxygen
light– independent reaction phase of photosynthesis where energy from light– dependent reactions is
used to produce glucose and additional ATP molecules
pigment molecules that absorb specific wavelengths of sunlight
electron transport chain series of proteins embedded in a membrane along which energized electrons
are transported; as electrons are passed from molecule to molecule, energy is released
NADH+ electron carrier molecule
Calvin cycle series of reactions during the light– independent phase of photosynthesis in which
simple sugars are formed from carbon dioxide using ATP and hydrogen from the light– dependent
reactions
cellular respiration chemical process where mitochondria break down food molecules to produce
ATP; the three stages are glycolysis, the citric acid cycle, and the electron transport chain
anaerobic chemical reactions that do not require the presence of oxygen

aerobic chemical reactions that require the presence of oxygen
glycolysis in cellular respiration, series of anaerobic chemical reactions in the cytoplasm that breaks
down glucose into pyruvic acid; forms a net profit of 2 ATP molecules
citric acid

Coacervates Lab
Purpose or Objective: The purpose of performing this lab is to create greater understanding of the
origin of life hypothesis by creating coacervates and testing some of their properties, in this case
permeability.
Experiment 1: The purpose of this lab is to discover which pH coacervates are most abundant at, and
how they develop and behave.
Extension: The purpose of the lab extension was to test a coacervate membrane's permeability to
crystal violet dye.
Background and Theory:
Essential Question: At what pH will coacervates be most abundant, and when will they start forming
Hypothesis 1: I predict that coacervates will start developing at a pH of 5 and will be most abundant
at a pH of 4.5. Since the coacervates form after adding hydrochloric ... Show more content on
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It is not known how life came to be on the earth, but it is proven that it has evolved over time, and
life is unified by a common ancestor. In the 1920s, a hypothesis was created by scientists Alexander
Oparin and J.B.S. Haldane, that predicted that the first life forms were formed in an acidic
primordial sea. Oparin believed that a string of of chemical reactions within an aquatic environment
had led to the formation of coacervates. Coacervates are aggregates of organic polymers that have
life like characteristics, but are not alive. When Oparin created coacervates, he used a couple
different solutions of macromolecules to form these aggregates, and he discovered that the
coacervates had a selectively permeable membrane. It is thought that coacervates may have been
one of the first pieces in the origin of life on Earth. This lab uses a carbohydrate, gum arabic, and a
protein, gelatin to create coacervates. As we carry out the procedures to create the coacervates, we
will observe how coacervates are formed and what characteristics they share with life. Through
doing this, we will gain better understanding of the Oparin–Haldane hypothesis and the possible
explanation of how life was formed on Earth. ( Carolina™

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 Helpwriting.net ...
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

The Viscosity of Liquids
39. The Viscosity of Liquids
After studying the present lecture, you will be able to
Define viscosity and viscosity coefficient
Outline the method to measure viscosity using Ostwald viscometer
Determine the average molecular weight of a polymer
Determine the surface concentration of 1–butanol in aqueous solution
Measure the distribution coefficient of a solute betweenn two solvents
39.1 Introduction
Viscosity, one of the transport properties, arises because of intermolecular attractive and relatively
long–range forces. Viscosity coefficient ([pic]), a specific constant characteristic of a liquid could be
expressed by the following equation of Poiseuille.
[pic] ... Show more content on Helpwriting.net ...
The constant a is sensitive to the shape and varies from zero for hard sphere or 0.5 for random coils
to 2.0 for rigid rods.
Variation of specific viscosity of a solution [pic] (specific viscosity or reduced viscosity) is defined
as [pic], where [pic] is the viscosity of solution i and [pic] the viscosity of pure solvent) with the
concentration of solute is given by the equation:
[pic] (39.7)
where, c is concentration of the polymer in g/mL and K is a constant.
The determination of average molecular weight of polyvinyl acetate in acetone and methanol uses
the following Procedure:
Prepare solution of polyvinyl acetate in acetone containing approximately 1 mg/ mL. From this
prepare four more solutions of 0.2, 0.4, 0.6, 0.8 mg/ mL by dilution. Measure the specific viscosity

of all the four solutions as described above.
Repeat the above experiment with solution of polyvinyl acetate in methanol.
Plot [pic] versus c and calculate [pic] and K from equation (2). Also, using the empirical formula (1)
and constant of K and a from the table given below, determine the molecular weight of polyvinyl
acetate in these two solvents.
|Solvent |K |a |
|Acetone |21.4 x 105 |0.68 |
|Methanol |38 x 10–5 |0.59 |
39.4 Excess Surface Energy

1, 4-Dichlorimene Lab Report
Benzoic acid and 1,4–dichlorobenzene are extracted from an unknown sample of powder. Both
components are identified by comparing their experimental melting points to known literature
values.
Discussion. Extraction is the transfer of a solute from one phase to another. Solubility depends on
polarity, and goes by the rule "like–dissolves–like." Most organic molecules are more soluble in
organic solvents than in water. If the organic solvent is immiscible with water, then when the
organic solvent dissolves organic molecules this solution forms a layer separate from the water layer
forming two layers: an organic layer, and an aqueous layer. When the two layers are mixed together,
small amounts of components from each layer will dissolve in the other layer, establishing an
equilibrium between the two layers. In order to extract solute from solvent A to solvent B, several
extractions with small portions of the solvent B are more efficient than a single extraction with the
total ... Show more content on Helpwriting.net ...
Since the unknown powder was known to contain both an organic compound and an acid, we had to
add aqueous sodium hydroxide in order to draw out the acid and its conjugate base into the aqueous
layer. When the base was added to the separatory funnel, it attracted the acid and formed an
immiscible aqueous layer under the liquid layer containing the organic compound. The funnel was
shaken to draw out as much acid as possible, and the aqueous layer was withdrawn from the funnel.
Aqueous sodium hydroxide was added a second time to pull out even more acid that may have
remained in the organic layer, and was withdrawn as well. In hopes of drawing out any remaining
acid from the organic layer, water, a polar substance, was added to the separatory funnel to form a
final aqueous layer that was withdrawn and added to the previous

Egg Osmosis Using ' Deshelled ' Chicken Eggs
Egg Osmosis Using "Deshelled" Chicken Eggs
Martekka Crawford
India Williams
Desiree Counts
Mark Beckford
Biology 1611–Sec 348
Dr. M. Jones
September 17, 2015
Georgia Perimeter College– Decatur
Introduction
The osmolarity of a solution is the concentration measured of a solute. To determine the
concentration of a solution, one must first understand what osmosis is and how it works. Osmosis is
the spontaneous passage or diffusion of water or other solvents through a semipermeable membrane
according to the Britannica Encyclopedia. The semipermeable membrane is one that blocks the
passages of dissolved substances such as solutes. This process, in more recent times, provides a
more accurate study of how water can diffuse across a cell membrane when water molecules have a
high concentration to an area in which they have a low concentration. It was originally studied in
1877 by plant physiologist, Wilhelm, Pfeffer. (Britannica Encyclopedia 2015).
Osmosis is described in one of three ways when comparing more than one solution. The cell's
external and internal environment helps determine tonicity, which is defined as how the cell reacts to
its environment. When the cell's environment is equal in osmolarity to itself and there is no change,
it is considered an isotonic solution. When the environment has a higher osmolarity, shrinkage
occurs and it is considered a hypertonic solution. When the environment has a lower osmolarity,
swellings occurs and it is considered hypotonic.

Description Of Povidone
Nonproprietary Names: BP: Povidone, USP: Povidone
Synonyms: E1201; Kollidon; Plasdone; poly[1–(2–oxo–1–pyrrolidinyl)ethylene]; PVP; polyvidone;
polyvinylpyrrolidone; 1– vinyl–2 – pyrrolidinone polymer.
Chemical Name and CAS Registry Number: 1– Ethenyl –2– pyrrolidinone homopolymer [9003–39–
8]
Empirical Formula and Molecular Weight: (C6H9NO)n 2500–3 000 000
The USP 28 describes povidone as a synthetic polymer consist of linear 1– vinyl–2–pyrrolidinone
groups, polymers of various molecular weights results due to differing degree of polymerization .
Structural Formula: Functional Category: Disintegrant; suspending agent; dissolution aid; tablet
binder.
Applications in Pharmaceutical Formulation or Technology: Povidone is widely used in
pharmaceutical formulations, mainly used in solid–dosage forms. In tableting, povidone dispersions
are used as binders for wet– granulation processes. Povidone is also used as a solubilizer in oral and
parenteral formulations to improve dissolution of poorly soluble drugs from solid–dosage forms.
Povidone solutions may also be used as coating. ... Show more content on Helpwriting.net ...
Povidone with K–values equal or less than 30 are prepared by spray–drying technique and with
higher K–value or equal to 90 are prepared by drum drying technique.
Typical Properties:
Acidity/alkalinity: pH = 3.0 – 7.0 (5% w/v aqueous solution).
Density (bulk): 0.29–0.38 g/cm3 for

Scientific Explanation Of Reaction Lab Answers
Discussion of Results and Scientific Explanations:
The goal of this laboratory was learn how to use the Spectrophotometer to analyze the phosphate
content in colas. This is important because the consumers believe that the buffering capacity of
phosphate within the colas will settle their upset stomachs. A spectrophotometer, or Spec 20,
measures how much a chemical substance absorbs and transmits. The next goal is to determine the
relationship between absorbance and transmittance. Transmittance is a measurement of the amount
of light that passes through a substance. So if the transmittance is 100 percent then the absorbance is
zero. Also another vital goal is to analyze the relationship between absorbance and the wavelength
of the two color ... Show more content on Helpwriting.net ...
Phosphate is not able to be absorbed alone so AVM, ammonium vanadomolybdate, is necessary to
add to give the solution a slight yellow color. This allows the solutions to be absorbed. Once this is
understood, you can start the experiment. Start by making a blank solution containing 6mL of water
and 3mL of AVM. Next, take .101M and use the equation M1V1=M2V2 to dilute the solution to
.0002M, this is shown in Calculation 8. Use this equation to make four dilutions of PO4–3 with
AVM. Samples of the four dilutions were run through the spectrophotometer at a wavelength of
360nm, and percent transmittance for each was recorded. The four concentrations of PO4–3 are
shown in Table 3. Running the 4 diluted samples through the Spec 20 and finding the %T, between
18% and 85%, allows you to determine the absorbance as well. Concentration and absorbance for
PO4–3 is now able to be compared which is shown in Figure 3. As concentration of the phosphate
ion goes up, the percent absorbance goes up, this is a direct relationship. This coincides with Beer's
Law, A=abC, A being the absorbance, C being the concentration, a being the absorptivity and b
being the cell path length.3 The higher concentration of a solution, the more light is absorbed. The
slope of the calibration curve is y=543949x–1.4302, y being the percent absorbance and x being the
phosphate content, this is shown in Figure

The Effect Of Ph Solution Of Feed Phase On The Removal...
Figure. 7. Effect of pH solution of feed phase on the removal efficiency of citric acid
Transport conditions: Feed phase: citric acid 10–2 M, pH 2–12. Stripping phase: deionized water,
pH=6.8. Membrane: 12.60 cm2 of surface area, Calix[4]resorcinarene (0.15 g/g mixture of
polymers), 0.03 ml 2–NPOE/g mixture of polymers. Values obtained after 5 days of
experimentation.
3.8 Stability of PIMs
In this study, one PIM was reused, whereas the feed and strip phases were replaced after one cycle
with fresh ones in 5 experiments and each experiment lasted from 4 days. As observed in Fig. 8. The
initial flux of PIM shows a gradual decrease with increasing of cycle's reuse, which may be caused
by the loss of carrier from membrane [37]. ... Show more content on Helpwriting.net ...
Conclusion
In this study, a polymer inclusion membrane was prepared and succevally applied for the removal of
citric acid from synthetic wastewater. The mixture of CTA and CA was found to be the optimum
base polymer for quantitative transport of citric acid. Moreover, the nature of carrier especially alkyl
chain length, stirring rate, and pH of feed phase are also important factors affecting the increased
rate of citric acid transport. Hence, from results obtained it can be seen that the investigated
calix[4]resorcinarene are effective extractants for citric acid and that their extraction abilities depend
on the alkyl chain length of the substituent in the macrocycle. Choosing the appropriate length of
alkyl chain, very selective system can be designed. The excellent efficiency for the citric acid
transport by the proposed PIM system reveals its potential application for the selective removal,
concentration and purification of citric acid from different media.
References
[1] K.L. Kalra, H.S. Grewal, Fungal production of citric acid, Biotechnol. Adv., 13 (2) (1995) 209–
234.
[2] M. Pazouki, P.A. Felse, J. Sinha, T. Panda, Comparative studies on citric acid production by
Aspergillus niger and Candida lipolytica using molasses and glucose, Bioprocess Eng., 22 (2000)
353–361.
[3] A.A. Ghoreyshi, F.A. Farhadpour, M. Soltanieh, M. Abdelghani, Transport of small polar
molecules across nonporous

Spectrophotometric Determination of Ascorbic Acid...
Spectrophotometric determination of Ascorbic acid Concentration in an Unknown Solution
Introduction:
The naturally occurring organic compound with antioxidant properties is Ascorbic acid shortly
referred as (AA). Normally the color of Ascorbic acid is white, but in some cases of impure samples
it appears yellow in color. Ascorbic acid is solid in state. In water it dissolves well to give mildly
acidic solutions. Ascorbic acid is one form ("vitamer") of vitamin C [1]. So, Ascorbic Acid (AA) in
other terminology also called as Vitamin C. This ascorbic acid majorly helps in the maintenance of
DNA, Lipids, Proteins and others in their original active, normal form.
The name of the anion Fe(CN)64− is mentioned as Ferrocyanide. ... Show more content on
Helpwriting.net ...
| | | | |
|0.00 |0.00 |2.00 |2.00 |0.00 |0.00 |0.000 |
|0.10 |0.00 |1.90 |2.00 |0.25 |0.00 |0.204 |
|0.20 |0.00 |1.80 |2.00 |0.50 |0.00 |0.473 |
|0.30 |0.00 |1.70 |2.00 |0.75 |0.00 |0.761 |
|0.40 |0.00 |1.60 |2.00 |1.00 |0.00 |1.038 |
|0.50 |0.00 |1.50 |2.00 |1.25 |0.00 |1.310 |
|0.60 |0.00 |1.40 |2.00 |1.50 |0.00 |1.544 |
|0.70 |0.00 |1.30 |2.00 |1.75 |0.00 |1.801 |
|0.80 |0.00 |1.20 |2.00 |2.00 |0.00 |2.024 |
|part 2 | | | | | | |
|0.00

Spring Practice Chemistry Final
Spring Practice Final 2011
Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
____ 1. The volume of a gas is 400.0 mL when the pressure is 1.00 atm. At the same temperature,
what is the pressure at which the volume of the gas is 2.0 L? a. | 0.5 atm | c. | 0.20 atm | b. | 5.0 atm |
d. | 800 atm |
____ 2. The pressure of a sample of helium is 2.0 atm in a 200–mL container. If the container is
compressed to 10 mL without changing the temperature, what is the new pressure? a. | 200 atm | c. |
100 atm | b. | 0.10 atm | d. | 40. atm |
____ 3. A sample of argon gas at standard pressure occupies 1000. mL. At constant temperature,
what volume does the gas occupy if ... Show more content on Helpwriting.net ...
| 30.ºC | d. | 273ºC |
____ 19. A sample of gas at 6.0 atm and 5.0ºC increases in temperature to 35ºC. If the volume is
unchanged, what is the new pressure? a. | 5.4 atm | c. | 36 atm | b. | 6.6 atm | d. | 42 atm |
____ 20. The volume of a sample of oxygen is 300.0 mL when the pressure is 1 atm and the
temperature is 27.0ºC. At what temperature is the volume 1.00 L and the pressure 0.500 atm? a. |
22.0ºC | c. | 0.50 K | b. | 45.0ºC | d. | 227ºC |
____ 21. Suppose that the pressure of 1.00 L of gas is 380. mm Hg when the temperature is 200. K.
At what temperature is the volume 2.00 L and the pressure 0.750 atm? a. | 1.00 K | c. | 219ºC | b. |
600. K | d. | 67.0 K |
____ 22. The volume of a gas collected when the temperature is 11.0ºC and the pressure is 710 mm
Hg measures 14.8 mL. What is the calculated volume of the gas at 20.0ºC and 740 mm Hg? a. | 7.8
mL | c. | 14.6 mL | b. | 13.7 mL | d. | 15 mL |
____ 23. The volume of a sample of hydrogen is 798 mL and it exerts 621 mm Hg pressure at
5.00ºC. What volume does it occupy at standard temperature and pressure? a. | 520. mL | c. | 745 mL
| b. | 640. mL | d. | 960 mL |

____ 24. A 30.–L sample of gas exerts 200. mm Hg pressure at 10ºC. What volume does the gas
have at 300. mm Hg and 25ºC? a. | 9.0 L | c. | 21 L | b. | 17 L | d. | 42 L |
____ 25. A 70.0 L sample of gas at 20.0ºC and 600. mm Hg expands to 90.0 L at 15.0ºC. What is the
new gas pressure?

Recrystallization Of Organic Chemistry Lab Report
Veneta Dinova
CHM 2210 L
Section: 006
Lab Partner: Jake Bodway
TA: Benjamin Pollard
Experiment 4: Recrystallization of Pure Phthalic Acid, Benzoic Acid and Naphthalene
Introduction Section
Recrystallization is a technique frequently used in organic chemistry to purify solid organic
compounds. The goal of this technique is to allow organic compounds to form crystal lattice
structures, and to remove any of the impurities that do not align within this crystal structure.1 The
theory behind recrystallization revolves around entropy; as heat will cause a organic compound to
dissolve (increase in entropy), a decrease in heat will then allow that organic compound to reform
(decrease in entropy) and become purer.2
The recrystallization technique utilizes the ability of a compound to dissolve within a hot solvent
and produce a solution. As this solution cools, the solute reforms without impurities in a crystal
lattice structure.1 For this to work properly, an appropriate solution that will not dissolve the solute
at low temperatures, but will at high temperatures, must be used.1 There is no single solvent that
will work well for every solute's recrystallization; different solvents are better suited for some
solutes than others.2 Some impurities that do not dissolve within the solvent can be filtered out
while the solution is still hot, while other impurities that readily dissolve within the solvent shouldn't
recrystallize with the pure substance (as they are not concentrated enough to

Colloids For Research Paper
Solutions, colloids, and suspensions are all types of mixtures. Suspensions and colloids are
classified as heterogeneous mixtures and solutions are classified as the homogeneous mixture.
Solutions are single atoms that never settle and are transparent which also means clear. Colloids are
aggregates of atoms, molecules, or ions, they can settle and they are transparent with a Tyndall
effect. Suspensions are clumps of particles such as sand and their movement is by gravity with the
translucent effect. An example of a solution is sugar dissolving in water because the solute the sugar
is being dissolved in the solvent which is the water it is basically two substances evenly mixed
together. Some examples of Colloids is plasma proteins, albumins, ... Show more content on
Helpwriting.net ...
An example of a nonelectrolyte is C6H12O6 – glucose because it can not dissociate into ions
whenever it is in an aqueous solution.
Solubility is the quantity of a particular substance solid, liquid, or gas solute that can dissolve in a
particular solvent, yielding a saturated solution(biology online). The solubility of solids increases
with the temperature. The increasing of the temperature allows the solvent molecules to easily
detach the solute molecules that are held by intermolecular attractions. The solubility of gases is a
little more complicated because as the temperature increase the kinetic energy also increases which
causes more motion of the molecules to move more freely. There're two ways for material to be
dissolved the first way is dipole to dipole which is molecular and the second way is dipole to ion
which is ionic.
When an ionic compound like NaCl dissolves in water, we end up with a positive Na and negative
Cl in a

Solubility Product Constant Lab Report
Determine the solubility product constant (Kₛₚ) of calcium hydroxide (Ca(OH)₂) by using the
concentrations of calcium and hydroxide found during titration.
The solubility product constant, or Kₛₚ, represents the level at which a substance dissolves in a
solution at equilibrium. A higher Kₛₚ value means the more soluble a substance is in a solution. The
solubility product constant, similar to solubility, is temperature dependent. When writing the
expression for Kₛₚ solids and liquids do not appear since their concentrations do not change, only
aqueous solutions are expressed.
The Kₛₚ equation would be written as Kₛₚ= [C]^c[D]^d. The reason the reactant aA is not included is
because it is a solid, therefore not represented in the expression. ... Show more content on
Helpwriting.net ...
So the 0.050 concentration of HCl affects how fast the rate of solubility will occur. If there was a
higher concentration the faster the reaction would occur.
The temperature affects how effective the solute molecules break apart. The higher the temperature
the more kinetic energy is formed, which increases the effectiveness of finding the solubility
constant.
If the Ca(OH)₂ was not filtered correctly during the experiment the concentrations of the experiment
would be off. If cloudiness still remained in the solute after filtration then the more HCl would have
been used to find the solubility of calcium hydroxide. Filtering correctly helps with the effectiveness
of breaking apart molecules to find specific concentrations to find the total solubility product
constant. The best option to finding the correct final product is to filter until clear.
If too much or too little of the saturated solute was used how could that affect the experiment? More
solute means more solvent, but however, with the final calculations, the final product should be the
same if data was recorded

Bezophenone Lab Report
The solubility of a substance is the amount of that substance that dissolved in a given amount of
solvent. Solubility of substance is affected by some factors such as temperature, pressure and the
nature of the intermolecular forces or interionic forces in both the solute and the solvent. The
solubility of solid and liquids usually increase as the temperatures increase. Differ with gases, its
solubility decrease with increasing temperature. For pressure, it has minimal effect on the solubility
of solids and liquids. Both the solute and the solvent have two different categories which are polar
and non polar. Theoretically, polar molecules are best solvated by polar solvent molecules and non
polar molecules are best solvated by non polar solvent. This concept is known as "like dissolves
like". This is because of the intermolecular forces between the molecules in substances. ... Show
more content on Helpwriting.net ...
The purpose of this part is to prove the concept of "like dissolves like". Basically, since all the solute
and the solvent are different in polarity, this part will give different result based on their polarity.
Second part of this experiment will focused on the solubility of three different alcohols which are
methanol (CH_3 OH), 1–butanol (C_4 H_9 OH) and 1–octanol (C_8 H_17 OH) in water and
hexane (C_6 H_14). The purpose of this part is to investigate the relationship between the
hydrocarbon chains with its solubility characteristics. In brief, the longer the hydrocarbon chains,
the lower the solubility of the

Reaction Lab Report Essay
Important equations:
Molarity = moles of solute / liters of solution
E = hν = hc/λ
Elight = hνlight = hc/λlight = ΔE = EUO – EOO
Objective:
We will be using various combinations of distilled water, hydrogen peroxide, malonic acid, ascorbic
acid (Vitamin C), acetic acid (Vinegar), starch solution, laundry detergent, iodine tincture,
manganese sulfate, and sulfamic acid to produce multiple pairs of solutions labeled Solution A and
Solution B. The goal is to either observe the process of fluorescence or the absence of fluorescence.
Fluorescence is the chemical property of generating light after undergoing the process of absorbing
and emitting a certain amount of energy, directly causing a physical change in the substance's color.
Mixing Solution A and Solution B, while viewing the results under UV light from time to time,
should result in the new solution constantly ... Show more content on Helpwriting.net ...
Make sure to pour Solution B into Solution A, then mix throughly.
Observations:
After swirling the resulting solution, its appearance kept cycling through the color yellow and
appearing colorless. However, there was constantly a small patch of blue residue caused by some
undissolved starch powder. There was some gas formation during this process. After 5 minutes, we
stopped swirling the beaker and let it sit in the fume hood. 15 to 20 minutes later, the solution began
to turn dark blue.
PART B:
Making ascorbic acid (Vitamin C solution)
Obtain one vitamin C tablet and place it into a mortar and pestle. Crush the tablet until it becomes a
fine powder. Next, move the powder into a new 50 mL beaker and pour exactly 1 tablespoon of
distilled water into the beaker. Then, obtain a glass stir rod to partially mix the solution, allowing

any remaining solids to drown to the bottom of the beaker. Keep track of this beaker since the acid
will be utilized throughout the remainder of the

Purifying A Compound Of Benzoic Acid
Introduction
The purpose of this lab was to purify a compound of benzoic acid through the process of
recrystallization. This was done in a couple steps, first dissolved the product to be recrystallized in
hot solvent then filtered off impurities, then filtered to isolate the crystals from the recrystallizing
solvent [1]. For this method to work there were many different theories that play a role, one of the
theories is solubility. Solubility is a chemical property that a solute is able to dissolve in a solvent
[2]. This plays a huge role in the experiment as the first step was to dissolve the crude benzoic acid
in water. Solubility was important because if the crude benzoic acid did not dissolve within the
solvent then the impurities would ... Show more content on Helpwriting.net ...
In the first step the benzoic acid had to be dissolved in the solvent, water, so that the impurities can
separate from the benzoic acid. Next, the solution was cooled slightly to add decolorizing charcoal
in order to remove the impurities. Then, the solution was heated up again for 20 minutes. Then, the
solution was filtered so the charcoal wouldn't be in the final product. Finally, when filtering with the
Buchner funnel the water was cooled this was used to prevent the benzoic acid from dissolving in
the water and being flushed away with the rest of the water.
The melting point of benzoic acid is 122.35 °C [5]. The melting point determined from the
experiment is a range from 118°C – 120°C. The reason for the experiment producing a melting
range compared to a melting point is due to impurities as well for the reason of a lower melting
point [1]. Impurities within the product lowers the melting point due to intermolecular forces, this
causes benzoic acid to not have as strong of a bond together in its crystal structure as there are
impurities in the way. This allows a lower level of heat to melt the benzoic

Solution Of A Weak Acid And Sodium Hydroxide Solution
Objectives:
To conduct a reaction between solutions of a weak acid and sodium hydroxide.
Determine the half–way point of titration of an acid–base reaction.
To calculate the pKa and the Ka for the weak acid.
To calculate Molar Mass of a weak acid from the titration results.
To determine the identity of a weak acid.
Introduction: The purpose of this experiment is to identify an unknown weak acid by titration with a
standard sodium hydroxide solution.
The pH of the titration solution will be monitored using a pH meter. The resulting titration curve
will then be used to determine the equivalent molecular weight and dissociation constant (Ka ) of
the unknown weak acid. These values will then let you determine the identity of the ... Show more
At the halfway point of each titration, the concentration of acid remaining in the solution is equal to
half of its initial concentration.
At the halfway point of the "Titration 1" the concentration of H2X is
and
Taking the negative log of this yields: pH = pKa
From the titration curve, we can determine the pH at the halfway point of the titration and thus
determine the pKa of the acid. From pKa = Log Ka we can determine the Ka of the acid. Since
this is a diprotic acid, this corresponds to Ka1. This information can be used to help identify the acid
because pKa and Ka values for a large number of mono and polyprotic acids are known.
Table 1. Some Characteristics of Selected Weak Acids
Acid Name Molar Mass, g/mol pKa
Acetic Acid 60.05 4.76
Ascorbic Acid 176.12 4.10 (pKa1)
Benzoic Acid 122.12 4.202
Boric Acid 61.83 9.24 (pKa1)
KHP
204.23 5.4

Maleic Acid 116.07 1.9 (pKa1)
Sodium Phosphate Monobasic
NaH2PO4x H2O 137.99 7.21 (pKa2)
Procedure:
SAFETY NOTE: In case of a spill on the skin of an acid or a base, wash off immediately with
plenty of water for at least 15 minutes. Get medical attention if symptoms occur.
Waste Disposal: Do not return excess amount of NaOH solution into the original container, place it
in the properly labeled waste container instead. Solids can go into the "Solid Waste" jar. All
solutions

Lab 7: Ph, Dissociation, Hydrochloric Acid Solutions
Kevin Malakov 6/28/15 CHM 3001 Professor Charnick Lab #7: pH, Dissociation, Hydrolysis, and
Buffers Lab Abstract: The purpose of this experiment was to "compare calculated and measured pHs
of a series of hydrochloric acid and acetic acid solutions." "Measure the pH of various salt
solutions." Also to "compare measured and calculated pHs of: a buffer solution." (Lab Manual Page
15) Concentation pH %error HCl pH %error HC2H3O2 1x10–1M 0% 6.9% 1x10–2M 5.0% 2.94%
1x10–3M 3.33% 2.56% 1x10–4M 0% 2.22% Solution pH %error Distilled Water 7.14% Original
buffer Solution 5.06% Distilled water with added 6M HCl 9.48% Buffer Solution with added 6M
HCl 29.0% Distilled water with added 6M NaOH 1.55% Buffer Solution with added 6M NaOH
46.4% ... Show more content on Helpwriting.net ...
Overall, the results for the pH of HCl and HC2H3O2 was close to that of the theoretical pH. The K
values had errors most probably due to contamination, improper dilution, and bad mixing. Also
some of the measured pH's from the water buffer solutions had high %errors may be due to
contamination, bad mixing, and not having the precise volumes. The changes in the observed
percent ionization of acetic acid with dilution are consistent with Le Chatelier's principle. As a
solution becomes more dilute ionization increases. This will make the equilibrium to shift to the
right in order in this case to make more

tonicity on cell membrane lab report Essay
Effects of Tonicity on Cell Membrane
Abstract The purpose of this experiment was to determine the effects of tonicity on a cell membrane
using red blood cells, potato strips and three unknown solutions (A, B, C). First three slides were
prepared containing RBC's and unknown solutions A, B and C. A control slide was prepared only
using RBC's. After observing each slide under the microscope it was determined that unknown
solution A was hypertonic because the RBC appeared to have shrunk. The RBC in unknown solution
B appeared to be swollen, therefor, the tonicity of unknown solution B was hypotonic. Unknown
solution C showed no change to the RBC shape, it was suggested that unknown solution C was
isotonic. To confirm the tonicity ... Show more content on Helpwriting.net ...
Cells placed in a hypertonic solution will shrink as the solvent leaves the cells.
Plant cells react differently to osmosis than animal cells. When an animal cell is placed in a
hypertonic solution, water will leave the cell causing it to shrink, this is known as crenation. When a
plant cell is placed in a hypertonic solution the cell membrane will pull away from the cell wall,
making the plant flaccid, this is known as plasmolysis. When an animal cell is placed in a hypotonic
solution, water will rush in to the cell, causing it to swell and sometimes burst. A plant cell placed in
a hypotonic solution will also swell due to water rushing in, but will resist rupturing due to the rigid
cell wall. Plant cells become more rigid in a hypotonic solution.
In this activity we will be observing the effects of potato slices and red blood cells being placed in
varying molar levels of NaCl.
Methods
The materials used for the first part of the experiment comprised of the following: a microscope, 4
slides, 4 slide covers, blood samples, lancet, a sheet of paper towel, 3 test tube droppers, Solutions
A, Solutions B, and Solution C.
Blood samples from a volunteer within the group were used to conduct the experiment. The
volunteer's hands were thoroughly washed and an alcohol swab was applied to further sanitize the
hands. To gather the blood samples needed, a lancet was properly placed on the forefinger and a
firm pressure was applied, which activated the needle inside to

Disadvantages Of Refractometer
INTRODUCTION
A refractometer is aneoptical device that takes advantage of the fact that light passing through a
liquid bends or refracts. The refractometer is a tool. It is used to help you select higher quality of
foods containing more vitamins and minerals. They are also used to determine the concentration of
dissolved solids in a solution. Cooking oil, molasses, syrup, and other thick liquids require a
refractometerqcalibrated to read 30–90 Brix. Refractometer also is used in wine making. (Harrill,
1998) refractometer is also used to test to quality of fruits and vegetables.
A hydrometer is an instrument used to measure the density of a liquid as compared to that of water.
Hydrometers usually consist of a calibrated glass tube ending in ... Show more content on
Helpwriting.net ...
Why?
Temperature is an essential parameter because the index of refraction is affected by temperature.
The speed of light in a liquid will increase when the temperature increases. For instance, according
to Hanson (2006), when there is 1°C increasing in temperature, many organic liquids the index of
refraction decreases by nearly %0.05
What are the advantages and disadvantages of both instruments in measuring total soluble solid
content? Refractometer advantages: İnexpensive instrument
Refractometer disadvantages: Tedious calibration No instrument protocol Operator dependent
readings( limited accuracy) Long and difficult thermosetting (water bath is required after each
experiment)
Hydrometer advantages: Quick instrument Simple method Inexpensive instrument
Hydrometer disadvantages; Breakable glassware especially be careful when it is dropped into
solution Difficult to clean and dry it needs to be sure that it is cleaned well because not enough to
clean can cause measurement mistake Operator dependent readings Large sample volume required
("Comparision of different measuring techniques for density and

Separating Acids and Neutral Compounds by Solvent Extraction
Separating Acids and Neutral Compounds by Solvent Extraction Introduction The purpose of this
experiment was to use solvent extraction techniques in order to separate a mixture consisting of a
carboxylic acid (p–toulic acid), a phenol (p–tert–butylphenol), and a neutral compound (acetanilide).
Extraction is the process of selectively dissolving one or more of the compounds of a mixture into
an appropriate solvent, the solution that contains these dissolved compounds is called an extract
(Manion, 2004). Impurities that are present in the solution can be removed by extracting them from
the original solvent into another solvent. This is done by mixing two immiscible (insoluble to one
another) solvents (Manion, 2004). By mixing the ... Show more content on Helpwriting.net ...
This process was then repeated two more times with subsequent additions of 10 mL of the 0.5M
aqueous NaHCO3 and the aqueous layers drained off into the above mention labeled 100–mL
beaker. Finally 5 mL of deionized water was placed into the funnel and mixed. The water was then
drained off into the beaker containing the aqueous solution extracts. The solution was then saved
until need later in the experiment. The extraction of the p–tert–butylphenol was then carried out in
the exact same fashion as the p–toulic acid, with the exception that the aqueous solution added to the
remaining ether solution was 10 mL of 0.5M NaOH. The solution was mixed and the gas was in the
funnel, along with the extraction of the aqueous layer three times into a clean and labeled 100–mL
beaker. As in the previous step an addition of 5 mL of deionized water was used in the final
extraction step. The extracted solution was also saved for later in the experiment as was the ether
layer remaining in the separatory funnel. 3 The retained solution from the NaHCO3 extraction was
used to precipitate the P–toulic acid. Drop wise 3M HCl was added to the extracted solution
carefully until no more precipitate was formed and the solution tested acidic, with a pH reading less
than 3 as indicated by pH paper testing. A piece of clean filter paper was then weighed and the mass
recorded in a lab notebook. A vacuum filtration system was constructed with a Buchner funnel

Recrystallization And Identification Of Unknown
Recrystallization and Identification of Unknown Arsalan Kouser Chemistry 2270 Laboratory,
Section 18 Instructor: Kyle Fulle October 8, 2014 Abstract In this laboratory project, Compound "E"
was identified as N–Phenylsuccinimide. The % yield was 60.5 %. The melting point of both
Compound "E" and N–Phenylsuccinimide was 153–154 ⁰C, as verified through experimentation; the
official melting point range of N–Phenylsuccinimide is 153–157 ⁰C. The yield of dibromobenzene
was 1 gram, and the % yield of dibromobenzene was 69.2%. The purpose of this experiment was to
purify an impure compound through recrystallization, and then identify it through measuring the
melting point. Introduction The main goal of this laboratory project was for an impure compound to
be purified through recrystallization, which entails clearing impurities from the compound, and
allows the separation of the pure product, which forms orange hexagonal crystals. The crystals will
have impurities attached to them initially during formation, but over time compounds will have all
the impurities removed as long as recrystallization is not too fast or slow. The pure compound will
then be used to isolate the melting point of the compound and determine its true identity. Impurities
would not allow proper identification of the compounds, as impurities would cause the compound to
melt at different temperatures; hence, this is the main importance of recrystallization. Other

Determining The Ksp Value For Silver Acetate Essay
Determining the Ksp value for silver acetate.
Introduction:
An equilibrium constant for a solid substance that is dissolving in an aqueous solution is represented
by the solubility product constant, where the concentrations of different ions from the solid
substance (compound) are used to calculate the solubility product constant. If the solubility product
constant vale is high then the substance is very soluble in an aqueous solution. The solubility
product constant is denoted by Ksp, and for a common reaction: aA(s) ⇌ cC(aq)+dD(aq)T
The Ksp= [C(aq)]c[D(aq)]d
The concentration of the solid (aA) doesn't contribute to the equilibrium constant because their
concentration doesn't change the expression of the equilibrium constant. Any change in their
concentration isn't that important as the ions and therefore they are taken out of the expression,
hence, the solubility product constant represents the amount of solid that can be dissolved in a
solution.
One important effect on the solubility ... Show more content on Helpwriting.net ...
The solution was swirled to induce precipitation, the swirling was for 30 minutes. The solution was
filtered through a dry filter paper and a dry funnel into a dry 250 ml beaker. The temperature of the
filtrate was then measured and recorded. A clean, dry burette was assembled and filled with the
potassium thiocyanate solution, the burette reading was recorded, then into a clean, 50 ml flask, 5.00
ml of the filtered silver acetate solution was pipetted. 30 drops of the indicator (saturated ferric alum
in 1.0 N HNO3), a few drop of the thiocyanate solution was added, then continued to be added
dropwise, with swirling after each addition, until one drop gives a permanent light orange colour.
The whole process of titrating silver acetate with potassium thiocyanate was repeated two more
times with batches of 5.00 ml of the saturated silver acetate

Gummy Bear Lab Report
Background: In my experiment, I am trying to see how different solutions varying in pH levels will
affect the shape and weight of gummy bears. The main ingredient in most gummy bears is gelatin.
Gelatin is a collagen. It is derived from animals such as pig skin, cow skin or bones. In the United
States, gummy bears are made of gelatin. In other parts of the world where eating pork is not
accepted, gummy bears are made with a substitute of gelatin. Some ingredients used to make
gummy bears include sugar, citric acid, gelatin, starch and food coloring. In this experiment, I hope
to see how osmosis and diffusion will play a role in the interaction between the gummy bears and
the different solutions. Osmosis occurs when water moves from low solute concentration to high
solute concentration. On the other hand, diffusion occurs when particles in the water move from
high concentration to low concentration. I also to seek to ... Show more content on Helpwriting.net
...
I think that more acid solutions will most likely affect the form and shape of a gummy bear. The
gelatin in the gummy bear result in weaker bonds due to the acidity of the apple cider vinegar
solution. The Smart water and tap water gummy bear were over expanded probably due to osmosis.
The water moved from outside the gummy bear into the gummy bear because there is a high solute
concentration in the gummy bears. The gummy bear in the honey solution probably did not expand
much due to the solute concentration of the water and gummy bear. It did lose its shape due to the
acidity of the solution. When put in alkaline conditions, such as salt water, the gummy bear will
most likely not lose its shape. All in all, the different pH levels of solutions can affect the form and
shape of a gummy bear. The more acidic a solution is, a gummy bear will most likely lose its form
and shape. The gummy bears most likely will expand due to osmosis that occurs within the solution
and gummy

Sing A Primary Standard To Analyze Acid And Base Solutions

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