Given $\underset{\text{strongacid}}{{\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}}{\text{\hspace{0.17em}+\hspace{0.17em}H}}_{\text{2}}\text{O\hspace{0.17em}}\to {\text{\hspace{0.17em}H}}_{\text{2}}{\text{O}}^{\text{+}}{\text{\hspace{0.17em}+\hspace{0.17em}HSO}}_{\text{4}}^{-}$

$\underset{\text{weak\hspace{0.17em}acid}}{{\text{HSO}}_{\text{4}}^{-}}{\text{+\hspace{0.17em}H}}_{\text{2}}\text{O\hspace{0.17em}}\rightleftharpoons {\text{\hspace{0.17em}H}}_{\text{3}}{\text{O}}^{\text{+}}{\text{\hspace{0.17em}+\hspace{0.17em}SO}}_{\text{4}}^{\text{2-}}{\text{,\hspace{0.17em}K}}_{\text{a}}{\text{\hspace{0.17em}=\hspace{0.17em}1.1\hspace{0.17em}×\hspace{0.17em}10}}^{\text{-2}}$

Thus, at equilibrium, $\left[{\text{H}}_{\text{3}}{\text{O}}^{\text{+}}\right]\text{,\hspace{0.17em}}\left[{\text{HSO}}_{\text{4}}^{-}\right]\text{\hspace{0.17em}and\hspace{0.17em}}\left[{\text{SO}}_{\text{4}}^{\text{2-}}\right]{\text{\hspace{0.17em}in\hspace{0.17em}0.50\hspace{0.17em}M\hspace{0.17em}H}}_{\text{2}}{\text{SO}}_{\text{4}}$ respectively, are

$\left[{\text{H}}_{\text{3}}{\text{O}}^{\text{+}}\right]$                       $\left[{\text{HSO}}_{\text{4}}^{-}\right]$                  $\left[{\text{SO}}_{\text{4}}^{\text{2-}}\right]$

0.51M                          0.49M                       0.01M

$0.49M 0.49M 0.01M$

$0.50M 0.50M 0.50M$

$0.51M 0.51M 0.51M$