CER 126 (B1): Thermodynamics of Materials March 29, 2022
Problem Set No. 2 Due : April 8, 2022
Name : ___________________________________________________
Answer the following ask questions.
1. The initial state of a quantity of monatomic ideal gas is P = 1 atm, V = 1 liter, and T =
373K . The gas is isothermally expanded to a volume of 2 liters and is then cooled at
constant pressure to the volume V. This volume is such that a reversible adiabatic
compression to a pressure of 1 atm returns the system to its initial state. All the changes
of state are conducted reversibly. Calculate the value of V and the total work done on or
by the gas.
2. Two moles of monatomic ideal gas are contained at a pressure of 1 atm and a temperature
of 300K; 34, 166J of heat are transferred to the gas, as a result of which the gas expands
and does 1216J of work against its surroundings. The process is reversible. Calculate the
final temperature of the gas.
3. One mole of monatomic ideal gas at 25°C and 1 atm undergoes the following reversibly
conducted cycle:
a. An isothermal expansion to 0.5 atm, followed by
b. An isobaric expansion to 100°C, followed by
c. An isothermal compression to 1 atm, followed by
d. An isobaric compression to 25°C.
The system then undergoes the following reversible cyclic process;
a. An isobaric expansion to 100°C , followed by
b. A decrease in pressure at constant volume to the pressure P atm, followed by
c. An isobaric compression at P atm to 24.5 liters, followed by
d. An increase in pressure at constant volume to 1 atm
Calculate the value of P which makes the work done on the gas during the first cycle
equal to the work done by the gas during the second cycle.
4. Calculate the change in the enthalpy and the change in entropy when 1 mole of SiC is
heated from 25°C to 1000°C. The constant-pressure molar heat capacity of SiC varies
with temperature as
5. One mole of N2 gas is contained at 273 K and a pressure of 1 atm. The addition of 3000 J
of heat to the gas at constant pressure causes 832 J of work to be done during the
expansion. Calculate
a. The final state of the gas
b. The values of Δ U and Δ H for the change of state
c. The values of cv and cp for N2
