20 mL of 0.15(M) HCl solution is mixed with 50 mL of 0.1(M) `CH_(3)COONa` solution. State whether the mixed solution will act as a buffer or not.

Explanation

Number of millimoles of `CH_(3)COONa` in 50 mL 0.1(M) `CH_(3)COONa=0.1xx50=5` and that of HCl in 20 mL `0.15(M)" "HCl=0.15xx20=3`.
The reaction between `CH_(3)COONa and HCl` as:
`CH_(3)COONa(aq)+HCl(aq)toCH_(3)COONa (aq)+NaCl(aq)`
Hence, 3 millimol of HCl+3 millimol of `CH_(3)COONa to 3` millimol of `CH_(3)COOH+3` millimol off NaCl. Therefore, at the end of the reaction, there remains 3 millimol of `CH_(3)COOH and (5-3)=2` millimol of `CH_(3)COONa`.
`therefore`The resulting solution consists of weak acid `(CH_(3)COOH)` and its salt `(CH_(3)COONa)`. so, its accts as a buffer.