Determine the info asked in the question for lime and soda ash dose design, in $m\frac{g}{L}$

as CaO and $N{a}_{2}C{O}_3,$ to soften the following water to a final hardness of $80\mathrm{.}00m\frac{g}{L}$

as $CaC{O}_3.$ The ion concentrations reported below are all as $CaC{O}_3.$ Assume lime is

$93$ percent pure and soda ash is $95$ percent pure. The total lime and soda in $m\frac{g}{L}$ as

$CaC{O}_3$ are nearly:

$C{a}^{2+}=155\mathrm{.}0$;$M{g}^{2+}=62\mathrm{.}0$;$HC{O}_3^{-}=135\mathrm{.}0$;$C{O}_2=12\mathrm{.}0$

A$)$ Total lime $=191$ and Total soda $=62m\frac{g}{L}$ as $CaC{O}_3$

B$)$ Total lime $=191$ and Total soda $=42m\frac{g}{L^{as}}CaC{O}_3$

C$)$ Total lime $=291$ and Total soda $=42m\frac{g}{L}$ as $CaC{O}_3$

D$)$ Total lime $=271$ and Total soda $=52m\frac{g}{L^{2sCaC{O}_3}}$