Question

Resultant molarity of $H^{+}$ ion in a mixture of $100mL$ of $0.1M{H}_{2}S{O}_4$ and $200mL$ of $0.1M{H}_{3}P{O}_3$ is:

• A. 0.1 M
• B. 0.2 M
• C. 0.267 M
• D. 0.133 M

Answer 1

Answer: (B)

$H^{+}$ (in $H_{2}S{O}_4-$ a dibasic acid $)=0.2M$

$H^{+}($ in $H_{3}P{O}_3-$ a dibasic acid $)=0.2M$

Total $\left[H^{+}\right]=\frac{M_1{V}_1+M_2{V}_2}{V_1+V_2}$

$=\frac{100\times 0.2+200\times 0.2}{300}=0.2M$