Question

2S+3O2 -> 2SO3 Indicate whether S or O2 is the limiting reactant, 3mol S 4mol O, 3mol S 5mol O, 3mol S 3mol? Elemental S reacts with O2 to form SO3 according to the reaction 2S+3O2 ---> 2SO3 For each of the given situations, indicate whether S or O2 is the limiting reactant.

Answer 1

Balanced chemical reaction: 2S + 3O₂ → 2SO₃.

1) Answer is: oxygen is limiting reactant.

n(S) = 3 mol; amount of sulfur.

n(O₂) = 4 mol; amount of oxygen.

From balanced chemical reaction: n(S) : n(O₂) = 2 : 3.

3 mol : n(O₂) = 2 : 3.

n(O₂) = (3 · 3 mol) ÷ 2.

n(O₂) = 4.5 mol; limiting reactant, because there is only 4 mol of oxygen.

2) Answer is: sulfur(S) is limiting reactant.

n(S) = 3 mol.

n(O₂) = 5 mol.

From balanced chemical reaction: n(S) : n(O₂) = 2 : 3.

n(S) : 5 mol = 2 : 3.

n(S) = 10 mol ÷ 3.

n(S) = 3.33 mol; there is only 3 mol of sulfur, so it is not enough.

3) Answer is: oxygen (O₂) is limiting reactant.

n(S) = 3 mol.

n(O₂) = 3 mol.

From balanced chemical reaction: n(S) : n(O₂) = 2 : 3.

3 mol : n(O₂) = 2 : 3.

n(O₂) = (3 · 3 mol) ÷ 2.

n(O₂) = 4.5 mol; limiting reactant, because there is only 3 mol of oxygen.