Two separate 1.00 L buffer solutions are prepared at the same pH using NH₃/NH₄⁺ ( pKb of NH₃ = 4.75).
• Buffer A: 0.20 M NH₃ and 0.20 M NH₄⁺
• Buffer B: 0.50 M NH₃ and 0.50 M NH₄⁺
A single addition of 0.010 mol of solid NaOH is made to each buffer. Which buffer—A or B—will experience the smaller increase in pH? Justify your answer in one or two sentences.