Question

$0.4$g of NaOH is present in one litre of the solution shows that $H^{+}$ concentration of the solution is?

Answer 1

1 Litre of solution contains 0.4 g of NaOH.

The molecular weight of NaOH is 40 g.

$\left[O{H}^{-}\right]=\frac{Weight}{molecularweight}\times \frac{1}{volume}=\frac{0.4}{40}\times \frac{1}{1}=0.01$

But $\left[H^{+}\right]\left[O{H}^{-}\right]=1\times {10}^{-14}$

So, $\left[H^{+}\right]=\frac{1\times {10}^{-14}}{0.01}=1\times {10}^{-12}M$