NEET-XII-Chemistry
c2022 year:2022
- #1The `` pH `` of the solution containing `` 50\, mL `` each of `` 0.10 \,M `` sodium acetate and `` 0.01 \,M `` acetic acid is [Given `` pK _{ a } `` of `` \left.CH _{3} COOH =4.57\right] ``
(A) `` 2.57 ``
(B) `` 5.57 ``
(C) `` 3.57 ``
(D) `` 4.57 ``digAnsr: BAns : Weak acid `` \left( CH _{3} COOH \right) `` and salt of weak acid-strong base `` \left( CH _{3} COONa \right) `` form an acidic buffer.
Sodium acetate `` \left( CH _{3} COONa \right)=0.10 \,M `` ;
Acetic acid `` \left( CH _{3} COOH \right)=0.01 \,M `` ;
`` pH `` of acidic buffer solution is given by
`` pH = pK _{ a }+\log \frac{[\text { Salt }]}{[\text { Acid }]} ``
`` =4.57+\log \left(\frac{0.1}{0.01}\right) ``
`` =5.57 ``