Question

Question: A solution of permanganate is standardized by titration with oxalic acid ${\text{(H}}_{\text{2}}{\text{C}}_{\text{2}}{\text{O}}_{\text{4}}\text{)}$. It required 28.97mL permanganate solution to react completely with 0.1058g of oxalic acid. The unbalanced equation for the reaction is

$\text{Mn}{{\text{O}}_{\text{4}}}^{\text{-}}{\text{(aq) +H}}_{\text{2}}{\text{C}}_{\text{2}}{\text{O}}_{\text{4}}\text{(aq)}\stackrel{\text{Acidic}}{\to }{\text{Mn}}^{\text{2 +}}{\text{(aq) + CO}}_{\text{2}}$

What is the molarity of the permanganate solution?

Short answer

Answer

The molarity of the permanganate solution is 0.01622M .

Step-by-step solution

Definition of molarity of a solution

The moles of solute present per liter of a solution is defined as molarity of the solution.

Calculation of the molarity of the solution

Balanced reduction half-reaction:

${\text{MnO}}_{\text{4}}^{\text{-}}+{\text{8H}}^{\text{+}}+{\text{5e}}^{\text{-}}\to {\text{Mn}}^{\text{2 +}}+{\text{4H}}_{\text{2}}\text{O}$

Balanced oxidation half-reaction:

${\text{H}}_{\text{2}}{\text{C}}_{\text{2}}{\text{O}}_{\text{4}}\to {\text{2CO}}_{\text{2}}+{\text{2H}}^{\text{+}}+{\text{2e}}^{\text{-}}$

Total balanced equation:

role="math" $$\begin{gathered} \text{2Mn}{{\text{O}}_{\text{4}}}^{\text{-}}\text{(aq)}+{\text{6H}}^{\text{+}}\text{(aq)}+{\text{5H}}_{\text{2}}{\text{C}}_{\text{2}}{\text{O}}_{\text{4}}\text{(aq)}\to {\text{2Mn}}^{\text{2 +}}\text{(aq)}+{\text{8H}}_{\text{2}}\text{O(l)}+{\text{10CO}}_{\text{2}}\text{(g)} \\ {\text{c(MnO}}_{\text{4}}^{\text{-}}\text{)}=\frac{\text{n}}{\text{V}} \\ =\frac{4.7\times {10}^{-4}\text{mol}}{0.02897\text{L}} \\ =0.01622\text{M} \end{gathered}$$

The molarity of the permanganate solution is$0.01622\text{M}$ .