CH301H
- Principles of Chemistry I: Honors Fall 2011, Unique 51040 Homework, Week 13 |

Homework,
week
13 Answer key 1. a) A sealed vessel containing an ideal gas at a pressure of 0.5 atm is opened in a room at approximately atmospheric pressure (1.0 atm). What happens? b) A sealed vessel containing an ideal gas at a pressure of 1.5 atm is opened in the same room. What happens? c) The pressure of a poisonous gas inside a sealed vessel is 1.47 atm at 20˚C. If the atmospheric pressure is 1.0 atm, what temperature must the container and its contents to cooled to so that the container can be opened with no risk for gas escaping?
2.
You need to
perform a reaction using the compound H a) Is there any value in this information whatsoever? b) At what temperature is this statement true, if the gas is at 1.0 atm?
3. Research
in
surface science is carried out using ultra-high vacuum
chambers that can
sustain pressures as low as 10 4.
The van der
Waals equation is a state function that can be used to
describe a non-ideal
gas. Use the
ideal and van der
Waals state functions to determine the pressure of 1 mole
of ethane (C a) In a container of volume 22.4 L at 273.15 K. b) In a container of volume 0.100 L at 1000 K. 5. Interstellar space has an average
temperature of 10 K and
average density of hydrogen gas of about 1 molecule m
6. A sample of argon gas is held in a 1 L vessel and maintained at 25˚C. At what pressure does the mean free path of the gas become comparable to the size of the container? You may assume the diameter of the argon atom is 1.9 Å.
7. The following table describes the pressure and temperature of Earth’s upper atmosphere as a function of altitude:
altitude
(km)
20.0 0.056 220
40.0
3.2
x 10
60.0
2.8
x 10
80.0
1.3
x 10 Assuming that the atmosphere is
composed of 80% N 8.
The interior
of the Sun is thought to consist of 36% H and 64% He by
mass, at a density of
158 g cm ^{-15}
A^{1/3} m, were A is
the mass
number. (The
size of the free
electron is 10^{-18} m, and is negligible compared
to the size of the
nuclei.) The
pressure in the
stellar interior is thought to be 2.5 x 10^{11}
atm.
a)
Determine the excluded volume of 1.0 cm b) Determine the temperature in the stellar interior based on this model. Would the van der Waals equation be more appropriate for this system? |