The addition of H2 to C=C double bonds is an important reaction used in the preparation of margarine from vegetable oils. If 58.0 mL of H2 and 58.0 mL of ethylene (C2H4) are allowed to react at 1.5 atm, the product ethane (C2H6) has a volume of 58.0 mL. Calculate the amount of PV work done, and tell the direction of the energy flow.