Styrene can be hydrogenated to ethyl benzene at moderate conditions in both the liquid and the gas phases. Calculate the equilibrium compositions in the vapor and liquid phases of hydrogen, styrene, and ethyl benzene at each of the following conditions:

(a) 3 bar pressure and 298 K, with a starting mole ratio of hydrogen to styrene of 2:1

(b) 3 bar pressure and 423 K, with a starting mole ratio of hydrogen to styrene of 2:1

(c) 3 bar pressure and 600 K, with a starting mole ratio of hydrogen to styrene of 2:1