Question

The pH of an aqueous solution containing $0.025M{H}_{2}S{O}_4$ and $0.005MHCl$ is:
${\log }_{10}\left(5.5\right)=0.74$

• A. 0.74
• B. 1.26
• C. 0.26
• D. 1.74

Answer 1

The correct option is B 1.26

Number of moles of $H^{+}$ coming from $H_{2}S{O}_4$ are,
$n_{H^{+}}=2\times 0.025\times V$
Number of moles of $H^{+}$ coming from $HCl$ are,
$n_{H^{+}}=0.005\times V$
Here final volume is $V_f=VL$
So, final concentration of $H^{+}$ will be:
$C_f=\frac{(2\times 0.025\times V)+(0.005\times V)}{V}=0.055MpH=-{\log }_{10}\left[0.055\right]pH=-{\log }_{10}[5.5\times {10}^{-2}]pH=2-0.74=1.26$