Subject: Physical Chemistry Topic: 1st, 2nd & 3rd Law of Thermodynamics

Il. Problem Solving (70 Pts) 1. (15 Pts) Calculate AU and AH for the transformation of one mole of an ideal gas from 27C and 1 atm to 327C and 17 atm. Cp = (20.9 + 0.042T) J/Kmol. 2. (20) A piston filled with 0.0400 mole of an ideal gas expands reversible from 50.0 mL to 375 mL at a constant temperature of 37C. As it does so, it absorbs 208 J of heat. Calculate Q, W, AU and AH for the process. 3. (10) In a given change in state, 44J of work are destroyed and the internal energy increases by 170J. If the temperature of the system rises by 10K, what is the heat capacity of the system? 4. (10 Pts) At a power plant, superheated steam at 560C is used to drive a turbine for electricity generation. The steam is discharged to a cooling tower at 38 C. Calculate the efficiency of this process. 5. (15 Pts) Determine the overall change in entropy for the following process using 1.00mol of He: He (298 K, 1.50atm) - He (100.0 K, 15.0atm) The heat capacity of He is 20.78 J/K.mol. Assume that helium acts ideally.\f