Which of the following statements is `//` are correct ?

Options

A. A buffer solution contains a weak acis and its conjugate base
B. A buffer soluiton shows little change in pH on the addition of a small amount of acid or base
C. A buffer solution can be prepared by mixing a solution of ammonium acetate and acetic acid
D. The addition of solid potassium cyanide to water increases the pH of water

Answer

A,B,C,D