Use the following equation to determine how many moles of c are needed to react with 0.500 mole of so2.

5c + 2so2 --> cs2 + 4co

The answer to your question is 1.25 moles of C

Explanation:

Reaction

                                5C  +  2SO₂   ⇒   CS₂  +  4CO

Check that the reaction is balanced

                          Reactant         Element        Product

                                5                   C                   5

                                2                    S                    2

                                4                   O                    4

Use proportions to find the moles of C needed.

                       5 moles of C  2 moles of SO₂

                       x  moles of C   0.500 moles of SO₂

                       x = (0.500 x 5) / 2

                       x = 1.25 moles of C