Which of the following will produce a buffer solution when mixed in equal volumes

Options

A. `0.1 mol dm^(-3) NH_(4)OH and 0.1 " mol " dm^(-3) `HCl
B. `0.05 " mol dm"^(-3) NH_(4)OH and 0.1 " mol "dm^(-3)` HCl
C. `0.1 " mol dm"^(-3)NH_(4)OH and 0.05 " mol dm"^(-3)` HCl
D. `0.1 " mol dm"^(-3) CH_(4)COONa and 0.1 " mol dm"^(-3)` NaOH

Answer

C

Explanation

When the concentration of (weak base) is higher than the strong acid (HCl) , a mixture of weak base and its conjugate acid is obtained, which acts at basic buffer.
`NH_(4)OH + HCl to NH_(4)Cl + H_(2)O `
`{:("initially","0.1M","0.05M",0),("After reaction","0.05 M",0,"0.05 M "):}`.