Chemistry - Ionic Equilibrium Question with Solution | TestHub

$\text{Ba}{\left({\text{NO}}_3\right)}_2+{\text{Na}}_2{\text{CO}}_3\to {\text{BaCO}}_3+2{\text{NaNO}}_3$
Here$\left[\mathrm{C}{{\mathrm{O}}_3}^{-2}\right]=\left[\mathrm{N}{\mathrm{a}}_2\mathrm{C}{\mathrm{O}}_3\right]=10^{-4}$$\mathrm{M}$
${\mathrm{K}}_{\mathrm{s}\mathrm{p}}=\left[\mathrm{B}{\mathrm{a}}^{+2}\right]\left[\mathrm{C}{{\mathrm{O}}_3}^{-2}\right]=5.1\times 10^{-9}$
$\left[\mathrm{B}{\mathrm{a}}^{2+}\right]\left[10^{-4}\right]=5.1\times 10^{-9}$
$\left[\mathrm{B}{\mathrm{a}}^{2+}\right]=5.1\times 10^{-5}$$\mathrm{M}$
At this value of$\left[\mathrm{B}{\mathrm{a}}^{2+}\right]=5.1\times 10^{-5}$$\mathrm{M}$precipitation just starts.