Question

Calculate the pH of $0.05\text{M}$ of $HCl$.
$\left(\text{Use}\log \right[5]=0.7,\log [10]=1)$

• A. $1.26$
• B. $1.3$
• C. $3$
• D. $5$

Answer 1

The correct option is B $1.3$

$HBr$ is strong acid so it will get dissociated completely.
$\left[H^{+}\right]=0.05\text{M}=5\times {10}^{-2}\text{M}$
$pH=-\log \left[H^{+}\right]=-\log (5\times {10}^{-2})=-\log 5+2\log 10=-0.7+2=1.3$