This is an **oxidation-reduction** (redox) reaction:

*SIV - 2 e- → SVI (oxidation)*

*MgII + 2 e- → Mg0 (reduction)*

*MgSO3* is a **reducing** agent, *MgSO3* is an **oxidizing** agent.

### Input interpretation

*MgSO3 → Mg + SO3*

Magnesium sulfur trioxide

### Balanced equation

Balance the chemical equation algebraically:

*MgSO3 → Mg + SO3*

Add stoichiometric coefficients, **c2**, to the reactants and products:

*c1MgSO3 → c2 Mg + c3SO3*

Set the number of atoms in the reactants equal to the number of atoms in the products for ** Mg, S **and

**:**

*O**Mg: c1 = c2*

*S: c1 = c3*

*O: 3c1 = 3c3*

Since the coefficients are relative quantities and underdetermined, choose a coefficient to set arbitrarily. To keep the coefficients small, the arbitrary value is ordinarily one. For instance, set c1 = 1 and solve the system of equations for the remaining coefficients:

*c1=1 c2=1*

*c3 = 1*

Substitute the coefficients into the chemical reaction to obtain the balanced equation:

**Answer**:

*MgSO3 → Mg + SO3*