0 . 01 moles of a weak acid HA   K a = 2 . 0 × 10 - 6 is dissolved in 1 . 0   L of 0 . 1 M…

$0.01$ moles of a weak acid $\mathrm{HA} \left({\mathrm{K}}_{\mathrm{a}}=2.0\times {10}^{-6}\right)$ is dissolved in $1.0 \mathrm{L}$ of $0.1\mathrm{M} \mathrm{HCl}$ solution. The degree of dissociation of $\mathrm{HA}$ is __________ $\times {10}^{-5}$ (Round off to the Nearest Integer). [Neglect volume change on adding $\mathrm{HA}$ and assume degree of dissociation $<<1$]