Chapter 9, Problem 9.47SP

The addition of H₂ to C=C double bonds is an important reaction used in the preparation of margarine from vegetable oils. If 50.0 mL of H₂ and 50.0 mL of ethylene (C₂H₄) are allowed to react at 1.5 atm, the product ethane (C₂H₆) has a volume of 50.0 mL. Calculate the amount of PV work done, and tell the direction of the energy flow.

${\text{C}}_{\text{2}}{\text{H}}_{\text{4}}\text{(g)}+{\text{H}}_{\text{2}}\text{(g)}\to {\text{C}}_{\text{2}}{\text{H}}_{\text{6}}\text{(g)}$