Make a distribution diagram for the various $Cr(VI)$ species as a function of $pH$ at $C{r}_T=1,{10}^{-2}$ and ${10}^{-4}M.$ Neglect activity corrections.

Equilibria: $Cr{O}_4^{2-}+H^{+}=HCr{O}_4^{-}$;$,log{K}_1=6\mathrm{.}5$

$HCr{O}_4^{-}+H^{+}=H_{2}Cr{O}_4$;$,log{K}_2=-0\mathrm{.}8$

$2HCr{O}_4=C{r}_2{O}_7^{2-}+H_{2}O,log{K}_a=1\mathrm{.}52$

$C{r}_2{O}_7^{2-}+H^{+}=HC{r}_2{O}_7^{-},log{K}_{2a}=0\mathrm{.}07$

$[Cr]$