Violia, a South Africa design, manufacture, testing and supply company has been asked to design an air vessel that can store air. A Chemical Engineering student from Unisa has been hired to test the vessel's capacity to withstand changes in temperature and pressure. The student has been given a vessel of capacity 12.3m3 which contains air at a pressure of 180kPa and a temperature of 42C. The vessel's pressure and temperature are reduced to 75kPa and 13C, respectively, by removing some air. The student needs to find the amount of air removed and the volume of this mass of air at the initial state of air. Take R=0.287kJ/kg.K for air. [12marks] QUESTION 2 A centrifugal compressor must compress a perfect gas with a molecular weight of 44. The perfect gas is compressed from 101.3kPa,27C to a pressure of 680kPa following the law PV1.2= constant. Take the specific heat at constant pressure of the gas as 0.846kJ/kg.K. Find the heat transfer and its direction