Buffer Solutions — Prelims Questions

Which of the following combinations will form an acidic buffer solution?

Calculate the pH of a buffer solution containing 0.20 M CH$_3$COOH and 0.10 M CH$_3$COONa. The $K_a$ for CH$_3$COOH is $1.8 \times 10^{-5}$.

A buffer solution contains 0.1 M NH$_3$ ($K_b = 1.8 \times 10^{-5}$) and 0.1 M NH$_4$Cl. What is the pH of this buffer?

Which of the following statements about buffer capacity is INCORRECT?

What happens to the pH of an acidic buffer solution when a small amount of strong acid is added?

Which of the following pairs cannot act as a buffer solution?