Question

A given weak acid (0.01 M) has $p{K}_a=6$ .The pH of the solution is

• A. 3
• B. 4
• C. 5
• D. 6

Answer 1

The correct option is B 4

The relation between $pH$ and $p{K}_a$ of a solution of a weak acid is : $pH=\frac{1}{2}(p{K}_a-\log C)$
Where , $p{K}_a=6$ and Concentration (C) is $0.01M$.

$pH=\frac{1}{2}p{K}_a-\frac{1}{2}\log C=\frac{1}{2}\times 6-\frac{1}{2}\log \left(0.01\right)pH=3+1=4$