Question

Which one of the following is a buffer solution?

a) 0.40 M HCN and 0.10 KCN

b) 0.20 M CH₃COOH

c) 1.0 M HNO₃ and 1.0 NaNO₃

d) 0.10 M KCN

e) 0.50 M HCl and 0.10 NaCl