Problem

Raw groundwater with analysis as tabulated below is to be softeried by an excess lime$-$soda process.

a$)$ Compute the concentration of each type of hardness $(CCH,CNH,MCH,MNH$

b$)$ Calculate the quantity of lime $(90\%$ purity$)$ and soda ash $(96\%$ purity$)$ to soften this water if a surplus of $35$

$m\frac{g}{L}$CaO is required to precipitate $M{g}^{2+}.$

Consider that $p{K}_{a1}$ and $p{K}_{a2}$ of $H_{2}C{O}_3$ are $6\mathrm{.}3$ and $10\mathrm{.}3,$ respectively.