Question

Equal Volumes of three acid solutions of pH 3, 4 and 5 are mixed in a vessel. What will be the $H^{\oplus }$ concentration in the mixture?

• A. $3.7\times {10}^{-3}M$
• B. $1.11\times {10}^{-3}M$
• C. $1.11\times {10}^{-4}M$
• D. $3.7\times {10}^{-4}M$

Answer 1

The correct option is D $3.7\times {10}^{-4}M$

For the given acids,
$\left[H^{+}\right]={10}^{-3}M,$
$\left[H^{+}\right]={10}^{-4}M,$
$\left[H^{+}\right]={10}^{-5}M$
$M=\frac{M_1{V}_1+M_2{V}_2+M_3{V}_3}{V}\therefore V_1=V_2=V_3$
$=\frac{({10}^{-5}\times 1)+({10}^{-4}\times 1)+({10}^{-3}\times 1}{3})=3.7\times {10}^{-4}M$