Question

0.1 l of ethylene gas and 0.1 l of hydrogen chloride gas react to form 0.1 l of ethyl chloride gas at 2 atm. Pressure. Calculate the pressure - volume work.

Answer 1

C2H4 +  HCl - - - - - - - - - > C2H5Cl

0.1 l          0.1 l                          0.1 l

V1 = 0.1 + 0.1 = 0.2 l

V2 = 0.1 l

The reaction will proceed at 2 atm. As it is an isothermal process, its work done will be equal to :

Work done = - P external x delta V

Work done = - P external x ( V2 - V1 )

Work done = - 2 x ( 0.1 - 0.2 )

Work done = 0.2 L atm

When it will convert to Joules,

Work done = 0.2 x 101. 3 J L-1 atm -1

Work done = 20.26 J