Unbalanced Equation:

KMnO₄ + MgS → K₂S + Mg(MnO₄)₂

Balancing Steps:

1. Balance the Manganese (Mn): There is one Mn on the left and two on the right. Add a coefficient of 2 in front of KMnO₄.

2KMnO₄ + MgS → K₂S + Mg(MnO₄)₂

2. Balance the Potassium (K): There are two K on the right and two on the left, so potassium is already balanced.

3. Balance the Sulfur (S): There is one S on the left and one on the right, so sulfur is already balanced.

4. Balance the Oxygen (O): There are eight O on the left and eight O on the right, so oxygen is balanced.

Balanced Equation:

2KMnO₄ + MgS → K₂S + Mg(MnO₄)₂

Therefore, the correct set of coefficients is:

* 2 KMnO₄

* 1 MgS

* 1 K₂S

* 1 Mg(MnO₄)₂