$N{a}_{2}C{O}_3$ solution contains $15\%$ carbonate $(\frac{w}{w}).$ By evaporation of water and

subsequent cooling to $278K.,80\%$ the carbonate is recovered as $N{a}_{2}C{O}_3*10H_{2}O.$ The

solubility of $N{a}_{2}C{O}_3$ at $278K$ is $9\%$ by weight.

a$.$ Draw the schematic view of the operation

b$.$ Find the amount of crystal produced $(32\mathrm{.}345kg)$

c$.$ Find the amount of water evaporated. $)$