Final answer:
The balanced chemical equation for the reaction between Na2SO4 and MgCl2 is Na2SO4 + MgCl2 → MgSO4 + 2NaCl.
Step-by-step explanation:
The balanced equation for the reaction of Na₂SO₄ with MgCl₂, producing MgSO₄ and NaCl, is as follows: Na₂SO₄ + MgCl₂ → MgSO₄ + 2NaCl, which corresponds to answer choice (a). In this reaction, sodium sulfate reacts with magnesium chloride in a double replacement reaction, forming magnesium sulfate and sodium chloride. The equation is balanced as written because there are equal numbers of each type of atom on both sides of the reaction.