Question

4 NaCl + 2 SO₂ + 2 H₂O + O₂ = 2 Na₂SO₄ + 4 HCl

A). If you start with 10 moles of each reactant, which will be the limiting reactant.

B). If you start with 100 grams of each reactant, which will be the limiting reactant.

Answer 1

From the balanced reaction:

4 NaCl + 2 SO2 + 2 H2O + O2 = 2 Na2SO4 + 4 HCl

(A) This reaction tells that the maximum moles of NaCl is used in the balanced reaction which is 4 mole. Hence, for 10 mole of reactants, NaCl will be the limiting reagent.

This is because for 10 mole of NaCl required SO2 = 10 x 5 / 4 = 5 mole Similarily,

required H2O = 5 mole

required O2 = 2.2 mole

(B) First calculate the moles for all reactants in 100g of reactants:

moles of NaCl = 100 / 58.44 = 1.71 mole (Molar mass of NaCl is 58.44 g/mol)

moles of SO2 = 100 / 64.06 = 1.56 (Molar mass of SO2 is 64.06 g/mol)

moles of H2O = 100 / 18.01 = 5.55 moles (Molar mass of H2O is 18.01 g/mol)

moles of O2 = 100 / 31.99 = 3.12 moles (Molar mass of O2 is 31.99 g/mol)

Here also the moles of NaCl is limiting reagent as others would be required less.