Given the reaction: S + O2 ---> SO2

How many moles of sulfur must be burned to give 0.567 moles of SO2?

The answer to your question is 0.567 moles of S

Explanation:

Data

moles of S = ?

moles of SO₂ = 0.567

Balanced chemical reaction

                S  +   O₂   ⇒   SO₂

      Reactants    Elements    Products

             1                   S                 1

             2                  O                2

Process

1.- Use proportions and cross multiplication to find the moles of Sulfur.

Consider the coefficients of the balanced chemical reaction.

                    1 mol of Sulfur 1 mol of SO₂

                     x                      0.567 moles of SO₂

                                  x = (0.567 x 1) / 1

                                  x = 0.567 moles of S