The first and second ionization constants of H_2 X are 2.5 × 10^-8 and 1.0 × 10^-13 respectively. The concentration of X^2- in 0.1 M H_2 X solution…

The first and second ionization constants of $\displaystyle \mathrm{H}_2 \mathrm{X}$ are $\displaystyle 2.5 \times 10^{-8}$ and $\displaystyle 1.0 \times 10^{-13}$ respectively. The concentration of $\displaystyle \mathrm{X}^{2-}$ in $\displaystyle 0.1 \mathrm{M} \mathrm{H}_2 \mathrm{X}$ solution is $\displaystyle \_\_\_\_$ $\displaystyle \times 10^{-15} \mathrm{M}$. (Nearest Integer)