1. Starting with 9.3 moles of O 2 , how many moles of H 2 S will be needed and how many moles of SO 2 will

be produced in the following reaction? SHOW YOUR WORK!

2 H2S + 3 O2 -> 2 SO2 + 2 H2O

Moles of H₂S needed = 6.2 mol

Moles of SO₂ produced = 6.2 mol

Explanation:

Given data:

Number of moles of O₂ = 9.3 mol

Moles of H₂S needed = ?

Moles of SO₂ produced = ?

Solution:

Chemical equation:

2H₂S + 3O₂      →    2SO₂ + 2H₂O

Now we will compare the moles of oxygen with H₂S.

                  O₂             :           H₂S

                    3             :             2

                   9.3            :         2/3×9.3 = 6.2 mol

Now we will compare the moles of SO₂ with both reactant.

                   O₂             :            SO₂

                    3              :               2

                   9.3            :         2/3×9.3 = 6.2 mol      

                 H₂S             :            SO₂

                    2              :               2

                   6.2            :          6.2 mol      

So 6.2 moles of  SO₂ are produced.