- 10 kg of water is stirred in an agitator with a 2 HP motor. Heat is added at the rate of 1 kW. Find the change in internal energy.
- 2 kg of air at 10 atm and 300
^{o}C is allowed to expand adiabatically to 5 times its original volume. Find the final volume, the work done and change in internal energy. C_{V}= 0.1714 kcal/kg.^{o}C - An insulated and non-conducting container filled with 10 kg of water at 20
^{o}C is fitted with a stirrer, which is made to turn by lowering a weight of 25 kg mass. The weight slowly falls a distance 10 meters while turning the stirrer. Assuming that all the work done by gravity is transferred to water, determine the internal energy change of water, and the final temperature. - Air is compressed from 2 atm absolute and 28
^{o}C to 6 atm absolute and 28^{o}C by heating at constant volume followed by cooling at constant pressure. Calculate the heat and work requirements and DE and DH of the air. - Water at 93.3
^{o}C is being pumped from a storage tank at a rate of 198.24 litres/min by a pump. The motor deriving the pump supplies energy at the rate of 2 HP. The water passes through a heat exchanger where it gives up heat at the rate of 1,68,000 cal/sec and is delivered to a second storage tank at an elevation of 15.24 meters above the first tank. What is the temperature of the water delivered to the second tank? Density of water at 93.3^{o}C = 60.1 lb/ft^{3}; specific heat of water = 1 - Calculate Q, W, DU and DH for the following:
- Isothermal compression
- Isometric followed by isobaric process.
- Water is pumped from a tank to a overhead tank 15 meters above using a 2 HP pump. The water rate is 100 kg/min. What is the change in enthalpy of the process?
- 220 kg of CO
_{2}gas at 27^{o}C and 1 atm is compressed adiabatically to 1/5th of its volume. It is then cooled to its original temperature. Find DQ, DU and W for each step and for the entire process.

Gas: Ideal, 2kmol

Initial conditions: 2 atm, 20 m^{3}, 300 K

Final conditions: 10 atm, 2 m^{3}, 300 K

© M.Subramanian, Lecturer, Chemical Engg, SVCE, Sriperumbudur - 602105, Tamil Nadu, INDIA