Chemistry
10th Edition
ISBN: 9781305957404
Author: Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher: Cengage Learning
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Textbook Question
Chapter 15, Problem 90AE
a. Calculate the pH of a buffered solution that is 0.100 M in C6H5CO2H (benzoic acid, Ka = 6.4 × 10−5) and 0.100 M in C6H5CO2Na.
b. Calculate the pH after 20.0% (by moles) of the benzoic acid is converted to benzoate anion by addition of a strong base. Use the dissociation equilibrium
C6H5CO2H(aq) ⇌ C6H5CO2-(aq) + H+(aq)
to calculate the pH.
c. Do the same as in part b, but use the following equilibrium to calculate the pH:
C6H5CO2-(aq) + H2O(l) ⇌ C6H5CO2H(aq) + OH-(aq)
d. Do your answers in parts b and c agree? Explain.
Expert Solution & Answer
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6.
a. Calculate the pH of a buffered solution that is 0.100 M in C6H5CO2H (benzoic acid, Ka = 6.4 x 10-5) and 0.100 M NaC6H5CO2.
b. Calculate the pH after 20.0% (by moles) of the benzoic acid is converted to benzoate anion by addition of a strong base. Use the dissociation equilibrium: C6H5CO2H (aq) + H2O (l) ⇌ C6H5CO2- (aq) + H3O+(aq)
c. Do the same as in part b, but use the following equilibrium to calculate the pH: C6H5CO2 -(aq) + H2O(l) ⇌C6H5CO2H (aq) + OH- (aq)
d. Do your answers in part b and c agree? Explain.
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In Part A, a 15.00 mL aliquot of a 0.155 mol L-1 3-methylbutanoic acid solution was titrated to its equivalence point with 11.7 mL of 0.198 molL-1
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Chapter 15 Solutions
Chemistry
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Ch. 15 - What are the major species in solution after...Ch. 15 - A friend asks the following: Consider a buffered...Ch. 15 - Mixing together solutions of acetic acid and...Ch. 15 - Sketch two pH curves, one for the titration of a...Ch. 15 - Sketch a pH curve for the titration of a weak acid...Ch. 15 - You have a solution of the weak acid HA and add...Ch. 15 - You have a solution of the weak acid HA and add...Ch. 15 - The common ion effect for weak acids is to...Ch. 15 - Prob. 12QCh. 15 - A best buffer has about equal quantities of weak...Ch. 15 - Consider the following pH curves for 100.0 mL of...Ch. 15 - An acid is titrated with NaOH. The following...Ch. 15 - Consider the following four titrations. i. 100.0...Ch. 15 - Figure 14-4 shows the pH curves for the titrations...Ch. 15 - Acidbase indicators mark the end point of...Ch. 15 - Consider the titration of 100.0 mL of 0.10 M...Ch. 15 - Consider the following two acids: pKa1 = 2.98;...Ch. 15 - How many of the following are buffered solutions?...Ch. 15 - Which of the following can be classified as buffer...Ch. 15 - A certain buffer is made by dissolving NaHCO3 and...Ch. 15 - A buffer is prepared by dissolving HONH2 and...Ch. 15 - Calculate the pH of each of the following...Ch. 15 - Calculate the pH of each of the following...Ch. 15 - Compare the percent dissociation of the acid in...Ch. 15 - Compare the percent ionization of the base in...Ch. 15 - Calculate the pH after 0.020 mole of HCl is added...Ch. 15 - Calculate the pH after 0.020 mole of HCl is added...Ch. 15 - Calculate the pH after 0.020 mole of NaOH is added...Ch. 15 - Calculate the pH after 0.020 mole of NaOH is added...Ch. 15 - Which of the solutions in Exercise 21 shows the...Ch. 15 - Prob. 34ECh. 15 - Calculate the pH of a solution that is 1.00 M HNO2...Ch. 15 - Calculate the pH of a solution that is 0.60 M HF...Ch. 15 - Calculate the pH after 0.10 mole of NaOH is added...Ch. 15 - Calculate the pH after 0.10 mole of NaOH is added...Ch. 15 - Calculate the pH of each of the following buffered...Ch. 15 - Calculate the pH of each of the following buffered...Ch. 15 - Calculate the pH of a buffered solution prepared...Ch. 15 - A buffered solution is made by adding 50.0 g NH4Cl...Ch. 15 - Calculate the pH after 0.010 mole of gaseous HCl...Ch. 15 - Calculate the pH after 0.15 mole of solid NaOH is...Ch. 15 - Some K2SO3 and KHSO3 are dissolved in 250.0 mL of...Ch. 15 - An aqueous solution contains dissolved C6H5NH3Cl...Ch. 15 - Calculate the mass of sodium acetate that must be...Ch. 15 - What volumes of 0.50 M HNO2 and 0.50 M NaNO2 must...Ch. 15 - Consider a solution that contains both C5H5N and...Ch. 15 - Calculate the ratio [NH3]/[NH4+] in...Ch. 15 - Carbonate buffers are important in regulating the...Ch. 15 - When a person exercises, muscle contractions...Ch. 15 - Consider the acids in Table 13-2. 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