Question

Complete and balance the following chemical equations:
(a) \(\text{MnO}_4^- + \text{C}_2\text{O}_4^{2-} + \text{H}^+ \to \) (b) \(\text{KMnO}_4 \xrightarrow{\text{Heat}} \) (c) \(\text{Cr}_2\text{O}_7^{2-} + \text{H}_2\text{S} + \text{H}^+ \to \)

Hint:

Always ensure to balance the number of atoms and charge on both sides of the reaction. Redox reactions often require you to consider electron balance as well.

Answer 1

(a) The balanced equation for the reaction between permanganate and oxalate in acidic medium is: \[ 2\text{MnO}_4^- + 5\text{C}_2\text{O}_4^{2-} + 16\text{H}^+ \to 2\text{Mn}^{2+} + 10\text{CO}_2 + 8\text{H}_2\text{O} \] (b) The reaction of potassium permanganate upon heating gives potassium manganate: \[ 2\text{KMnO}_4 \xrightarrow{\text{Heat}} 2\text{K}_2\text{MnO}_4 + \text{O}_2 \] (c) The reaction between dichromate and hydrogen sulfide in acidic medium is: \[ \text{Cr}_2\text{O}_7^{2-} + 3\text{H}_2\text{S} + 8\text{H}^+ \to 2\text{Cr}^{3+} + 3\text{SO}_2 + 4\text{H}_2\text{O} \]