CH353
- Physical Chemistry I Spring 2012, Unique 52135 Homework, Week 3 |

Homework,
week 3 Answer key
1. A chemical reaction takes place in a
container with a
cross-sectional area of 1 m 2. A
1 L sample
of 2.00 mol Ar gas is expanded isothermally at 0˚C to a final
volume of 5 L a)
reversibly, b) against a constant external pressure equal to the
final pressure
of the gas, and c) freely (against no external pressure).
Determine 3. (To see the following equations most clearly, you should download a copy of the pdf.) A monatomic gas obeys the following equation of state: Show that for a reversible, adiabatic expansion of a monatomic gas, ( (Hint, knowing the expansion is adiabatic, find
simple
expressions for 4. 1.00
mol of
a monatomic ideal gas is initially held at 300 K and 1.0 atm.
The gas is heated to 400 K reversibly
at constant volume. Determine
5. An ideal monatomic gas at 273.15 K and 1 bar is expanded adiabatically from 22.7 L to 45.4 L. What is the final temperature of the system? 6. If
you were
on the surface of the moon you would need to wear a space suit
with thermal
insulation. In
exploring the moon
you might generate 4 kJ of heat per kg of mass per hour.
If your body retains all of this heat
because the insulation, how much would your temperature change per
hour during
this activity? How
long would you
recommend for such a moon walk?
Assume your body mass is 65 kg and that your heat capacity
is
approximately that of water ( _{2}O_{(l)})
= 75.29 J K^{-1} mol^{-1}). |