Question

A given weak acid (0.01M ) 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

Given, $\left[\text{weak acid}\right]=0.01M$, $p{K}_a=6.$
pH of weak acid is given by
$pH=\frac{1}{2}p{K}_a-\frac{1}{2}\log C$
$pH=\frac{1}{2}\times 6-\frac{1}{2}\log \left(0.01\right)=3+1=4.$