UNIVERSITI MALAYSIA PERLIS
Pusat Pengajian Kejuruteraan Bioproses
ERT 108: Physical Chemistry
Tutorial 2
1) A heat engine uses reservoirs at 800°C and 0°C.
a. Calculate maximum possible efficiency
b. If qH is 1000 J, calculate the maximum -w and the minimum value of -qC
2) Calculate ΔS for each of the following changes in state of 2.50 mol of a perfect
monoatomic gas with CV,m =1.5R for all temperatures:
a. (1.50 atm, 400K)  (3.00 atm, 600K)
b. (2.50 atm, 20.0L)  (2.00 atm, 30.0L)
c. (28.5L, 400K)  (42.0L atm, 400K)
3) After 200 g of gold [cP = 0.0313 cal/(g °C)] at 120°C is dropped into 25.0 g of water at
10°C, the system is allowed to reach equilibrium in an adiabatic container. Calculate:
a. The final temperature
b. ΔSAu
c. ΔSH2O
d. ΔSAu + ΔSH2O
4) A sample consisting of 2.00 mol of diatomic perfect gas molecules at 250 K is
compressed reversibly and adiabatically until its temperature reaches 300 K. Given
that CV,m = 27.5 JK-1mol-1, calculate:
a. q
b. w
c. ΔU
d. ΔH
e. ΔS.
5) A system consisting of 1.5 mol CO2 (g), initially at 15°C and 9 atm and confined to a
cylinder of cross-section 100.0 cm2. It is allowed to expand adiabatically against an
external pressure of 1.5 atm until the piston has moved outwards through 15 cm.
Assume that carbon dioxide may be considered a perfect gas with CV,m = 28.8
JK-1mol-1, calculate:
a. q
b. w
c. ΔU
d. ΔT
e. ΔS