Assuming that Ba ( OH )_2 is completely ionised in aqueous solution under the given conditions the concentration of H_3 O^+ ions in 0.005 M aqueous…

Assuming that $\displaystyle \mathrm{Ba}(\mathrm{OH})_2$ is completely ionised in aqueous solution under the given conditions the concentration of $\displaystyle \mathrm{H}_3 \mathrm{O}^{+}$ions in $\displaystyle 0.005$ M aqueous solution of $\displaystyle \mathrm{Ba}(\mathrm{OH})_2$ at $\displaystyle 298$ K is \_\_\_\_ $\displaystyle \times 10^{-12} \mathrm{~mol} \mathrm{~L}^{-1}$. (Nearest integer)