What is limiting reactant in chemistry?

Chemistry question about limiting reactant?

• For each of the following reactions provide a balanced chemical equation and suppose exactly 5.00g of each reactant is taken. Determine which reactant is limiting, and calculate what mass of each product is expected. (Assume that the limiting reactant is completely consumed). Manganese (IV) oxide + sulfuric acid --> manganese (IV) sulfate + water I balanced the equation: MnO2 + 2H2SO4 --> Mn(SO4)2 + 2H2O I'm not sure what to do next!

• Answer:

  MnO2 + 2 H2SO4 → Mn(SO4)2 + 2 H2O (5.00 g MnO2) / (86.93691 g MnO2/mol) = 0.057513 mol MnO2 (5.00 g H2SO4) / (98.0791 g H2SO4/mol) = 0.050979 mol H2SO4 0.050979 mole of H2SO4 would react completely with 0.050979 x (1/2) = 0.0254895 mole of MnO2 but there is more MnO2 present than that, so MnO2 is in excess and H2SO4 is the limiting reactant. (0.050979 mol H2SO4) x (1/2) x (247.0645 g Mn(SO4)2/mol) = 6.30 g Mn(SO4)2 (0.050979 mol H2SO4) x (2/2) x (18.01532 g H2O/mol) = 0.918 g H2O