A 0.200 g sample of benzoic acid, ${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{COOH}$, titrated with a 0.120 M $\mathrm{Ba}{\left(\mathrm{OH}\right)}_2$solution. What volume of the $\mathrm{Ba}{\left(\mathrm{OH}\right)}_2$ solution is required to reach the equivalence point?

Substance	Molar mass
${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{COOH}$	$122.1\mathrm{g}.{\mathrm{mol}}^{-1}$

$\text{ Moles }=\frac{\text{ mass }}{\text{ Molar mass }}$

$\text{ Molarity }=\frac{\text{ moles }}{\mathrm{L}\text{ of solution }}$

The balanced acid-base reaction between ${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{COOH}$$${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}\text{COOH}$$ and Ba(OH)2$$\text{Ba(OH}{\text{)}}_{\text{2}}$$is as follows:

$\begin{array}{r}2{\mathrm{C}}_6{\mathrm{H}}_5\mathrm{COOH}\left(\mathrm{aq}\right)+\mathrm{Ba}\left(\mathrm{OH}{)}_2\right(\mathrm{aq})\\ \rightleftharpoons \mathrm{Ba}{\left({\mathrm{C}}_6{\mathrm{H}}_5\mathrm{COO}\right)}_2\left(\mathrm{aq}\right)+2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\end{array}$

$0.00682\mathrm{L}\times \frac{1000\mathrm{ml}}{1\mathrm{L}}=6.82\mathrm{ml}$

Thus, 6.82 ml of $\mathrm{Ba}{\left(\mathrm{OH}\right)}_2$is required to reach the equivalence point.