Question

The pH of the solution $0.1M$ $H_2{SO}_4\left(50mL\right)+0.4M$ $HCl$ $50\left(mL\right)$ is:

• A. $5$
• B. $7$
• C. $12$
• D. None of these

Answer 1

The correct option is D None of these

We first find the individual values of $\left[H^{+}\right]ion$
For $50mL0.1M{H}_{2}S{O}_4$,
$\left[H^{+}\right]$=$n\alpha C$=$2\ast 1\ast 0.1$=$0.2M$..........since, acid is strong, $\alpha$=1
SImilarly, for $50mL0.1MHCl$,
$\left[H^{+}\right]$=$n\alpha C$=$1\ast 1\ast 0.1$=$0.1M$..........since, acid is strong, $\alpha$=1
Hence, total $\left[H^{+}\right]$=$0.2+0.1$=$0.3M$
$pH$=$-lo{g}_{10}\left[H^{+}\right]$=$-lo{g}_{10}0.3$=$0.523$
So answer is None of these.(Option D)