:  4 HCl + MnO2 → MnCl2 + 2 H2O + Cl2Â
(33.7 g MnO2) / (86.93691 g MnO2/mol) = 0.38764 mol MnO2Â
(45.3 g HCl) / (36.4611 g HCl/mol) = 1.2424 mol HClÂ
(a)Â
1.2424 moles of HCl would react completely with 1.2424 x (1/4) = 0.3106 mole of MnO2, but there is more MnO2 present than that, so MnO2 is in excess and HCl is the limiting reactant.Â
(b)Â
(1.2424 mol HCl) x (1 mol Cl2 / 4 mol HCl) x (70.9064 g Cl2/mol) = 22.0 g Cl2Â
(c)Â
(77.7% of 22.0 g Cl2) = 17.1 g Cl2