Example $4\mathrm{.}4$ Mixing of Battery

You are asked to prepare a batch of $18\mathrm{.}63\%$ battery acid as follows: A mixing

vessel of old weak battery acid $(H_{2}S{O}_4)$ solution contains $12\mathrm{.}43\%H_{2}S{O}_4($the

remainder is pure water$).$ If $200kg$ of $77\mathrm{.}7\%H_{2}S{O}_4$ is added $($not many kilogr!$)$ to

the vessel, and the final solution is to be $18\mathrm{.}63\%H_{2}S{O}_4,E4\mathrm{.}4b.$

of battery acid have been made? See Figures E$4\mathrm{.}4$a and EA$.$