A gas at a pressure of 1.4MN/m2 and temperature of 360°c is expanded adiabatically to a pressure of 100KN/m2. The gas is then hearted at a constant volume until it again attain 360°c when its pressure is found to be 220KN/m2 and finally it is compressed isothermally until the original pressure of 1.4MN/m2 is attained. If the gas has a mass of 0.23Kg, determine the value of adiabatic index r, and the change in internal energy of the gas during the adiabatic expansion. (take Cp as 1.005KJ/KgK and R as 0.3015NM/KgK