Which of the following mixtures can be regarded as buffer ?

Options

A. 500 ml 0.2( M) `CH_(3)COOH +` 1000 ml 0.02 ( M ) NaOH
B. 500 ml 0.2( M) `CH_(3)COOH +` 300 ml 0.02 ( M ) NaOH
C. 500 ml 0.2( M) `CH_(3)COOH +` 500 ml 0.02 ( M ) NaOH
D. 500 ml 0.2( M) `CH_(3)COOH +` 500 ml 0.02 ( M ) `NH_(4)OH`

Answer

B,D