Which one of the following pairs of 0.100 mol L-1 solutions, when mixed, will produce a buffer solution?

A. 50. mL of aqueous CH3COOH and 25. mL of aqueous CH3COONa
B. 50. mL of aqueous CH3COOH and 25. mL of aqueous HCl
C. 50. mL of aqueous NaOH and 25. mL of aqueous HCl
D. 50. mL of aqueous CH3COOH and 100. mL of aqueous NaOH
E. 50. mL of aqueous CH3COONa and 25. mL of aqueous NaOH

1 answer

Technically, a weak acid/salt of the weak acid (or weak base/salt of the weak base) produces a buffered solution. Technically, again, with no concns listed in the answers, none of them will do. However, I think, in the spirit of the problem, that is understood to be equal concns of the mixture in A through E.
A will do it.
B is not a buffer but it has some buffering action versus acid. Adding a base makes a buffer.
C. NO.
D. No.
E. No.