Question

If equal volumes of $0.1M$ $HBr$ and $0.1M$ $KOH$ are mixed then which of the following is/are correct about the resulting solution?
(1) $\left[H_3{O}^{+}\right]=1.0{\times 10}^{-7}mol{L}^{-1}$
(2) $\left[{OH}^{-}\right]={1.0\times 10}^{-7}mol{L}^{-1}$
(3) $\left[K^{+}\right]=0.05mol{L}^{-1}$
(4) $\left[{Br}^{-}\right]=1.0mol{L}^{-1}$

• A. 1, 2 and 3 are correct
• B. 1 and 2 are correct
• C. 2 and 4 are correct
• D. 1 and 3 are correct

Answer 1

The correct option is A 1, 2 and 3 are correct

$HBr+KOH\to KBr+H_{2}O$

$KBr$ is neutral salt which has $pH=7$ so $\left[H^{+}\right]={10}^{-7}=\left[O{H}^{-}\right]$

$\left[KBr\right]=0.1M$ so $\left[K^{+}\right]=\left[B{r}^{-}\right]=0.05mol{L}^{-1}$