To determine the number of moles of sulfuric acid H2SO4 required to react completely with 5 moles of magnesium hydroxide Mg OH 2 , we need to first write the balanced chemical equation for the reaction:Mg OH 2 + H2SO4 MgSO4 + 2H2OFrom the balanced equation, we can see that 1 mole of Mg OH 2 reacts with 1 mole of H2SO4 to produce 1 mole of MgSO4 and 2 moles of H2O.Since we have 5 moles of Mg OH 2, we will need 5 moles of H2SO4 to react completely with it.