Equilibrium Question 421
Question: A buffer solution contains $ 6.4\times {10^{-5}} $ of acetic acid and $ 0.1M $ of sodium acetate. What will be its $ pH $ , if $ pK_{a} $ of acetic acid is 4.75 [MP PMT 1996]
Options:
A) 4.00
B) 4.75
C) 5.00
D) 5.25
Show Answer
Answer:
Correct Answer: B
Solution:
$ pH=pK_{a}+log\frac{[\text{ Salt }]}{[\text{ Acid }]} $ ; $ pH=4.75+log\frac{0.1}{0.1} $
$ pH=4.75+log1 $ ; $ pH=4.75 $
