Lab Assignment: Titration for Acetic Acid in Vinegar
Hands-On Labs, Inc.
Lab Report Assistant
This document is not meant to be a substitute for a formal laboratory report. The Lab Report Assistant is simply a summary of the experiment's questions, diagrams if needed, and data tables that should be addressed in a formal lab report. The intent is to facilitate students' writing of lab reports by providing this information in an editable file which can be sent to an instructor.
Exercise 1: Determining the Concentration of Acetic Acid
Data Table 1.NaOH Titration Volume.
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Initial NaOH Volume (mL)
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Final NaOH Volume (mL)
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Total volume of NaOH used (mL)
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Trial 1
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9
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2
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7
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Trial 2
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9
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0.5
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8.5
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Trial 3
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9
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3
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6
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Average Volume of NaOH Used (mL) :
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Data Table 2. Concentration of CH3COOH in Vinegar.
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Average volume of NaOH used (mL)
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Concentration CH3COOH in vinegar (mol/L)
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% CH3COOH in vinegar
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7.16
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0.716
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6
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Concentration CH3COOH in Vinegar = 0.00716L X 0.5/L X (1Mol CH3COOH/ 1 MolNaOH) X 1/ 0.005L
Concentration of CH3COOH in Vinegar = 0.716Mol
Questions
A. The manufacturer of the vinegar used in the experiment stated that the vinegar contained 5.0% acetic acid. What is the percent error between your result and the manufacturer's statement?
% Error = |(Experimental - Accepted) / Accepted| x 100
% Error = (6 - 5 / 5 ) x 100
= 20%
B. What challenges would you encounter with the titration if you had used apple cider vinegar or balsamic vinegar as the analyte instead of white vinegar? The white vinegar is made up of pure vinegar so the results will be more accurate than the apple cider vinegar or balsamic vinegar, the later has other "impurities" in them. The apple and balsamic has other properties which will interfere with the titration.
C. How would your results have differed if the tip of the titrator was not filled with NaOH before the initial volume reading was recorded? Explain your answer.
D. How would your results have differed if you had over-titrated (added drops of NaOH to the analyte beyond the stoichiometric equivalence point)?
E. If a 7.0 mL sample of vinegar was titrated to the stoichiometric equivalence point with 7.5 mL of 1.5M NaOH, what is the mass percent of CH3COOH in the vinegar sample?
F. Why is it important to do multiple trials of a titration, instead of only one trial?
General Chemistry
1.Write the ionic equation for dissolution and the solubility product (Ksp) expression for each of the following slightly soluble ionic compounds: (a) PbCl2 (b) Ag2S (c) Sr3(PO4)2 (d) SrSO4
2.Assuming that no equilibria other than dissolution are involved, calculate the molar solubility of each of the following from its solubility product:
(a) Ag2SO4
(b) PbBr2
(c) AgI
(d) CaC2O4·H2O
3. The following concentrations are found in mixtures of ions in equilibrium with slightly soluble solids. From the concentrations given, calculate Ksp for each of the slightly soluble solids indicated:
(a) AgBr: [Ag+] = 5.7 × 10-7 M, [Br-] = 5.7 × 10-7 M
(b) CaCO3: [Ca2+] = 5.3 × 10-3 M, [CO3 2-] = 9.0 × 10-7 M
(c) PbF2: [Pb2+] = 2.1 × 10-3 M, [F-] = 4.2 × 10-3 M
(d) Ag2CrO4: [Ag+] = 5.3 × 10-5 M, 3.2 × 10-3 M
(e) InF3: [In3+] = 2.3 × 10-3 M, [F-] = 7.0 × 10-3 M
4. Calculate the molar solubility of AgBr in 0.035 M NaBr (Ksp = 5 × 10-13).
5.A helium-filled balloon spontaneously deflates overnight as He atoms diffuse through the wall of the balloon. Describe the redistribution of matter and/or energy that accompanies this process.
6.Arrange the following sets of systems in order of increasing entropy. Assume one mole of each substance and the same temperature for each member of a set.
(a) H2(g), HBrO4(g), HBr(g)
(b) H2O(l), H2O(g), H2O(s)
(c) He(g), Cl2(g), P4(g)
7.Predict the sign of the entropy change for the following processes.
(a) An ice cube is warmed to near its melting point.
(b) Exhaled breath forms fog on a cold morning.
(c) Snow melts
8.Predict the sign of the entropy change for the following processes.
(a) An ice cube is warmed to near its melting point.
(b) Exhaled breath forms fog on a cold morning.
(c) Snow melts.
Attachment:- Titration_of_Acetic_Acid_in_Vinegar_Lab_Experiment.pdf