Open Question
Which of the following gives a buffer solution when equal volumes of the two solutions are mixed? (a) 0.10 M HF and 0.10 M NaF (b) 0.10 M HF and 0.10 M NaOH (c) 0.20 M HF and 0.10 M NaOH (d) 0.10 M HCl and 0.20 M NaF
Ch.17 - Applications of Aqueous Equilibria
Chapter 17, Problem 66
Which of the following solutions has the greater buffer capacity: 50 mL of 0.20 M NH4Br-0.30 M NH3 or 50 mL of 0.40 M NH4Br-0.60 M NH3? Explain.
Verified step by step guidance1
Identify the components of the buffer solution: NH4Br provides NH4+ ions, and NH3 is the weak base.
Understand that buffer capacity is the ability of a buffer to resist changes in pH upon the addition of an acid or base, and it is generally higher when the concentrations of the buffer components are higher.
Compare the concentrations of NH4+ and NH3 in both solutions. The first solution has 0.20 M NH4+ and 0.30 M NH3, while the second solution has 0.40 M NH4+ and 0.60 M NH3.
Recognize that the buffer capacity is directly proportional to the concentrations of the acid and base components. Therefore, higher concentrations of NH4+ and NH3 will result in a greater buffer capacity.
Conclude that the second solution, with 0.40 M NH4+ and 0.60 M NH3, has a greater buffer capacity than the first solution.
Related Practice
Textbook Question
Which of the following gives a buffer solution when equal volumes of the two solutions are mixed?
(a) 0.10 M NH3 and 0.10 M HCl
(b) 0.20 M NH3 and 0.10 M HCl
(c) 0.10 M NH4Cl and 0.10 M NH3
(d) 0.20 M NH4Cl and 0.10 M NaOH
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Textbook Question
Which of the following solutions has the greater buffer capacity: 100 mL of 0.30 M HNO2-0.30 M NaNO2 or 100 mL of 0.10 M HNO2-0.10 M NaNO2? Explain.
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Textbook Question
Calculate the pH of a buffer solution that is 0.20 M in HCN and 0.12 M in NaCN. Will the pH change if the solution is diluted by a factor of 2? Explain.
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Open Question
Calculate the pH of a buffer solution prepared by dissolving 4.2 g of NaHCO3 and 5.3 g of Na2CO3 in 0.20 L of water. Will the pH change if the solution volume is increased by a factor of 10? Explain.
Open Question
Calculate the pH of 0.250 L of a 0.36 M formic acid–0.30 M sodium formate buffer before and after the addition of (a) 0.0050 mol of NaOH. Assume that the volume remains constant. (b) 0.0050 mol of HCl. Assume that the volume remains constant.