Here's how to balance the chemical equation for the reaction between hydrobromic acid (HBr) and magnesium sulfite (MgSO₃):

Unbalanced Equation:

HBr + MgSO₃ → MgBr₂ + H₂O + SO₂

Balancing Steps:

1. Sulfur (S): There's one sulfur atom on each side, so it's already balanced.

2. Magnesium (Mg): There's one magnesium atom on each side, so it's balanced.

3. Hydrogen (H): There are two hydrogen atoms on the product side (H₂O) and one on the reactant side (HBr). To balance this, we'll put a coefficient of 2 in front of HBr:

2HBr + MgSO₃ → MgBr₂ + H₂O + SO₂

4. Bromine (Br): Now we have two bromine atoms on the reactant side and two on the product side (MgBr₂), so bromine is balanced.

5. Oxygen (O): There are three oxygen atoms on the reactant side (MgSO₃) and three on the product side (H₂O + SO₂), so oxygen is balanced.

Balanced Equation:

2HBr + MgSO₃ → MgBr₂ + H₂O + SO₂