sample of a $0\mathrm{.}120M$ potassium sulfate solution is mixed with $35\mathrm{.}5mL$ of a $0\mathrm{.}128M$ lead$($II$)$ acetate solution and the following precipitation reaction occur

$K_{2}S{O}_4(aq)+Pb(C_2{H}_3{O}_2{)}_2(aq)2K{C}_2{H}_3{O}_2(aq)+PbS{O}_4(s)$

$PbS{O}_4$ is collected, dried, and found to have a mass of $0\mathrm{.}999g.$