Lab Report 22 Acids and Bases (Final)
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Faulkner University *
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1312
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Health Science
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Dec 6, 2023
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Acids and Bases: Analysis
Messiah I. Hayes
Department of Health Science, Faulkner University
Professor Mark Brenneman
May 1,2022
Abstract
This lab focuses heavily on titrating an acid with a base. During this lab, students used titration
with a standardized base to determine the amount of acetic acid within vinegar. Not all parts of
this lab experiment were completed. Some students completed Part A only while others were
responsible for Part B only. The results for this lab showed that the moles of NaOH is equal to
the moles of acetic acid, which is 0.004394, 0.004524, 0.005031. The average molarity of acetic
acid was found to be equal to the molarity of NaOH which is 0.26M. This titration lab required a
delicate touch with the buret.
Introduction
It’s always strange noticing chemistry in modern society. The concepts learned
throughout the semester become more visible and comprehendible at the grocery store. Wine is
beverage that once gone bad is sour to the taste. The sourness is due to the presence of acetic
acid. This acid after formic acid, is the second simplest carboxylic acid. Acetic acid is also a
presence in other liquid substances found at the neighborhood Publix. One of those substances
being vinegar. About 4% of acetic acid is found within vinegar which makes it one of the main
components in it excluding water and other trace elements. It has been made known that vinegar
is mostly diluted acetic acid produced by the oxidation of ethanol and fermentation.
Being that vinegar is a dilute solution of acetic acid, a base must be used in titration.
Sodium hydroxide is used to neutralize the acid, because of its strong basic nature. Sodium
hydroxide dissociates within water to form ions. In order to find the concentration of an acidic
solution, one must titrate the acidic solution with a basic solution. Scientists use titrations to
detect the equivalence point. This is the point is when equal amounts of reactants have been
mixed.
In this lab experiment the technique of titration is heavily involved. This technique was
cultivated in previous labs and a relief to execute correctly. Titration has happened when the
clear solution has undergone a chemical reaction changing to a pinkish purple color. For the most
precise numbers, a student strives to catch the reaction at the earliest sign of change. The lighter
the shade of pink, the more sooner the change is registered. Another technique that was is in the
lab experiment was using the buret. This tool was used in previous labs before lab #22, so it
wasn’t difficult to use in this lab setting.
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These observations recorded in this experiment are the shade of pink from the titration.
Being that the goal of titrating is trying to achieve the lightest shade of pink possible, one must
be very care and intentional about using the buret for titrating. It only takes one wrong move and
the titration resembles a dark purple rather than a translucent pink. Mathematically the
calculation in this lab includes: finding moles of elements, determining the density of vinegar,
deviations and mass percent determining.
Methods
The procedures were done according to Murov, S. L. (2015). Experiments in General
Chemistry (6th ed). Stamford, CT: Cengage Learning, pages 265 -266.
Part B of this experiment
was not necessary to complete by instructor’s request. Only part A was completed in this lab.
Results
A.
Analysis of vinegar
Flask 1
Flask 2
Flask 3
Unknown vinegar letter
A
Mass of flask
128.22
119.47
111.31
Mass of flask + 5.00 ml
of vinegar
133.22
124.47
116.31
Mass of 5.00 ml of
vinegar
5.00
Density of vinegar
1.05
Molarity of sodium
hydroxide solution
0.26M
Final buret reading
19.7
27.4
38.00
Initial buret reading
3.80
10.0
18.65
Vol. NaOH soln.
16.90
17.4
19.35
Moles of NaOH
0.004394
0.004524
0.005031
Moles acetic acid
0.004394
0.004524
0.005031
Average molarity of
acetic acid in vinegar
0.26
Deviation from
molarity average
Average deviation of
molarity
Mass percent of acetic
acid in vinegar
1.
Suggest experimental modifications you could make if the acid to be titrated has low
solubility in water.
-
One of the things that would improve the results of this titration could be
using a volumetric cylinder to measure out the solutions more precisely.
2.
Some of the
Learning Objectives
of this experiment are listed on the first page of this
experiment. Did you achieve the
Learning Objectives
? Explain in detail.
-
The first objective was achieved in the calculation portion of part A.
-
The second objective was achieved in the calculations of part A.
Discussion
These lab results reflect the results gathered from a previous lab. Being that acetic acid is
equivalent to NaOH the results are quite comparable. As it relates to the information discussed in
the literature section, the amount of acetic acid in the vinegar became determinable through
titrations. Future uses of this titration experiment can be used in food safety organizations. Foods
like vinegar, mayonnaise, and ketchup are foods that contain amounts of acetic acid. Using
titration experiments, food safety groups work to make sure those doses are too acidic or basic.
Conclusion
This lab required students to use most of the skills that were experienced in prior labs.
Some of the problems within this lab came from faulty titration execution. Being that titrating is
such a meticulous task, there’s a very thin line separating success from sadness. The student
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responsible for trial 2’s titration had some trouble being on the successful side of that thin line.
Other possible errors within this lab could come from calculations of the data table. The biggest
lessons learned throughout this semester which apply to this lab, are to clean as you go and have
a plan for conducting each lab. These labs have many steps and can be quite long. With that
being the case, the lab finishes sooner when all nonessential tools are gathered and cleaned
before continuing onward. The only modification that would make this lab more precise is using
a volumetric cylinder to add solutions to the Erlenmeyer flask. This was a good final lab to close
out the semester.