Question

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

Solutions

Verified
Step 1
1 of 5

First we need to determine oxidation numbers.

$\text{MnO}_4^{-} (\text{aq})+ \text{H}_2\text{C}_2\text{O}_4 (\text{aq}) \rightarrow \text{Mn}^{+2} (\text{aq}) + \text{CO}_2 (\text{g})$

$\textbf{Oxygen}$ is always -2 except in peroxides. Compounds must always have neutral charge. Knowing that we can calculate oxidation number for any compound. For $MnO_4^{-}$ we see that we have 4 molecules of oxygen so its oxidation number $-2\times{4}=-8$ but we see a negative charge so we add $+1$ and now we have $-8+1=-7$.

As we mentioned, compounds always need to have neutral charge, so we need to cancel that negative charge, so that means that oxidation number for $\textbf{Manganese}$ is +7.

Using that logic we calculate oxidation numbers for the rest of the elements:

$\textbf{Hydrogen}$ is always +1 and we know that Oxygen is -2, so we calculate that the oxidation number for $\textbf{Carbon}$ is +3.

For our products, we have already written charge for $\textbf{Manganese}$ +2, and we calculate that the oxidation number for $\textbf{Carbon}$ is +4.

## Recommended textbook solutions

#### Chemistry: The Molecular Nature of Matter and Change

7th EditionISBN: 9780073511177 (4 more)Patricia Amateis, Silberberg
3,832 solutions

#### Chemistry

9th EditionISBN: 9781133611097 (6 more)Steven S. Zumdahl, Susan A. Zumdahl
5,602 solutions

#### Chemistry

10th EditionISBN: 9781305957404 (3 more)Donald J. DeCoste, Steven S. Zumdahl, Susan A. Zumdahl
5,856 solutions

#### Chemistry, AP Edition

10th EditionISBN: 9781305957732Donald J. DeCoste, Steven S. Zumdahl, Susan A. Zumdahl
5,932 solutions