Calculate the $PH$ of solution produced by titrating $40\mathrm{.}00mL$ of $0\mathrm{.}03500MHCl($strong acid$)$ with

a$)20\mathrm{.}00mL$ of $0\mathrm{.}0200MBa(OH{)}_2($strong base$)$ solution

b$)60\mathrm{.}00mL$ of $0\mathrm{.}0200MBa(OH{)}_2($strong base$)$ solution

c$)$ What volume of $Ba(OH{)}_2$ solution is needed to reach the equivalence pointr Calculaty $pH$ at the equivalence point.

$2HCl+Ba(OH{)}_{2}BaC{l}_2+2H_{2}O$