The pH of a 0.01 M weak acid HX ( K_a=4 × 10^-10) is found to be 5. Now the acid solution is diluted with excess of water so that the pH of the…

The pH of a $\displaystyle 0.01$ M weak acid $\displaystyle \mathrm{HX}\left(\mathrm{K}_a=4 \times 10^{-10}\right)$ is found to be $\displaystyle 5$ . Now the acid solution is diluted with excess of water so that the pH of the solution changes to $\displaystyle 6$ . The new concentration of the diluted weak acid is given as $\displaystyle x \times 10^{-4} \mathrm{M}$. The value of $\displaystyle x$ is $\displaystyle \_\_\_\_$ (nearest integer)