Chapter 5, Problem 128RQ

It was found that a 20.0 mL portion of a solution of oxalic acid, ${\text{H}}_{\text{2}}{\text{C}}_{\text{2}}{\text{O}}_{\text{4}}$, requires 6.25 mL of $0.200M{\text{ K}}_{\text{2}}{\text{Cr}}_{\text{2}}{\text{O}}_{\text{7}}$ for complete reaction in an acidic solution. In the reaction, the oxidation product is ${\text{CO}}_{\text{2}}$ and the reduction product is ${\text{Cr}}^{\text{3+}}$. How many milliliters of $0.450M\text{ NaOH}$ are required to completely neutralize the ${\text{H}}_{\text{2}}{\text{C}}_{\text{2}}{\text{O}}_{\text{4}}$ in a separate 20.00 mL sample of the same oxalic acid solution?