In the Solvay ammonia process,what causes the precipitation of sodium bicarbonate?

Which is not an example of common ion effect?

When $1.88 \ g$ of $AgBr_{(s)}$ is added to a $10^{-3} \ M$ aqueous solution of $KBr$,the concentration of $Ag^{+}$ is $5 \times 10^{-10} \ M$. If the same amount of $AgBr_{(s)}$ is added to a $10^{-2} \ M$ aqueous solution of $AgNO_3$,the concentration of $Br^{-}$ is

When $H_2S$ gas is passed through a solution containing $HCl$,it precipitates the cations of the second group of qualitative analysis but not those belonging to the fourth group. This is because:

$A$ saturated solution of $BaSO_4$ at $25^\circ C$ is $4 \times 10^{-5} \ M$. The solubility of $BaSO_4$ in $0.1 \ M \ Na_2SO_4$ at this temperature will be:

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