The balanced equation for the reaction between magnesium chloride (MgCl2) and sulfuric acid (H2SO4) is:

MgCl2(aq) + H2SO4(aq) → MgSO4(aq) + 2HCl(g)

In this reaction, magnesium chloride reacts with sulfuric acid to form magnesium sulfate and hydrochloric acid gas. The coefficients in front of each compound indicate the relative number of molecules or moles of each substance involved in the reaction.