1 mole of a real gas is subjected to a process from (2 bar, 40 lit.,300K) to (4 bar, 30 lit., 400 K). If change in internal energy is 35 kJ then calculate enthalpy change for the process.

                       DH = DU + D(PV)

                        D(PV) = P₂V₂ – P₁V₁

                                          = 4 × 30 – 2 × 40

                                   = 40 liter -bar = 4 kJ

                  so      DH = 35 + 4 = 24 kJ

Calculate the work performed when 2 moles of hydrogen expand isothermally and reversibly at 25”C from 15 to 50 litres.

 

A gas absorbs 200J of heat and expands against the external pressure of 1.5 atm from a volume of 0.5 litre to 1.0 litre, Calculate the change in internal energy.

 

The internal energy of one mole of a gas is

 

A system does 100J work on surroundings by absorbing 150J of heat. Calculate the change in internal energy