Equilibrium Question 796
Question: Assuming that the degree of hydrolysis is small, the pH of 0.1 M solution of sodium acetate $ (K_{a}=1.0\times {10^{-5}}) $ will be:
Options:
A) 5.0
B) 6.0
C) 8.0
D) 9.0
Show Answer
Answer:
Correct Answer: D
Solution:
Sodium acetate is a salt of strong base and weak acid.
$ \therefore pH=7+\frac{1}{2}pK_{a}=\frac{1}{2}logc $ where $ pK_{a}=-\log K_{a}=-log{10^{-5}}=5 $
$ logc=log{10^{-1}}=-1 $
$ pH=7+\frac{5}{2}-\frac{1}{2}=9.0 $
