**Question: **An acidic buffer is obtained on mixing:

$100 \mathrm{~mL}$ of $0.1 \mathrm{M} \mathrm{CH}_{3} \mathrm{COOH}$ and $200 \mathrm{~mL}$ of $0.1 \mathrm{M} \mathrm{NaOH}$

$100 \mathrm{~mL}$ of $0.1 \mathrm{M} \mathrm{CH}_{3} \mathrm{COOH}$ and $100 \mathrm{~mL}$ of $0.1 \mathrm{M} \mathrm{NaOH}$

$100 \mathrm{~mL}$ of $0.1 \mathrm{M} \mathrm{HCl}$ and $200 \mathrm{~mL}$ of $0.1 \mathrm{M} \mathrm{CH}_{3} \mathrm{COONa}$

$100 \mathrm{~mL}$ of $0.1 \mathrm{M} \mathrm{HCl}$ and $200 \mathrm{~mL}$ of

$0.1 \mathrm{M} \mathrm{NaCl}$

Correct Option: , 3

**Solution:**
So finaly we get mixture of

$\mathrm{CH}_{3} \mathrm{COOH}+\mathrm{CH}_{3} \mathrm{COONa}$ that will work like acidic buffer solution.