5. The entropy of a system contained in an adiabatic enclosure (A) decreases during a reversible process (B) increases during a reversible process (C) decreases during an irreversible process (D) increases during an irreversible process (E) none of the above 6. For an ideal gas, P=210.3, where =Cp/Cv. After a reversible adiabatic process, the pressure of system reduces from 20atm to 4atm. The work is _ L atm. (A) 28.6 (B) 37.1 (C) 49.5 (D) 58.5 (E) 68.9 7. The normal boiling temperature of iron is 3330K. The rate of change of the vapor pressure of liquid iron with temperature is 3.72103atm/K. The molar latent heat of boiling of iron at 3330K is _ J. (A) 3423764 (B) 342376.4 (C) 34237.64 (D) 3423.764 (E) 342.3764 8. Gas constant is NOT (A) 8.314JK1mol1 (B) 8.63105eVK1mol1 (C) 5.191019eVK1mol1 (D) 1.987calK1mol1 (E) 0.082Latm1mol1