$($b$)$ You did a titration test for a water sample $(500mL).$ If the initial $pH$ of the water was $8\mathrm{.}8$ and the amount of $H_{2}S{O}_4(2\mathrm{.}59M)$ added by the end point was $1\mathrm{.}35mL,$ determine the alkalinity of the water. Write your answer both in eq$/$L and $m\frac{g}{L}$ as $CaC{O}_3.$

$($c$)$ If the end point $pH$ was $4\mathrm{.}5,$ write all possible compounds that may have contributed to the alkalinity. $($Hint$.$ Check the pKa table.$)$