Chemistry Reference
In-Depth Information
Example 2
Calculate the relative rate of diffusion of propane (C
3
H
8
) molecules
to methane (CH
4
) molecules.
V
M
44
.
1
CH
C
H
2
.
75625
1
.
66
4
=
3
8
=
=
=
V
M
16
.
0
u
C
H
CH
3
8
4
The less massive particles move faster, so we would say the methane
diffuses 1.66 times as fast as the propane, or the ratio of V
C
3
H
8
:V
CH
4
= 1:1.66
Try the following problems and check your answers at the end of the
chapter before moving on to the next lesson.
Lesson 8-6 Review
1.
Calculate the ratio of the velocity of carbon dioxide (CO
2
) molecules
to hydrogen (H
2
) molecules at the same temperature.
2.
Calculate the ratio of the velocity of argon (Ar) atoms to hydrogen
(H
2
) molecules at the same temperature.
3.
Calculate the ratio of the velocity of methane (CH
4
) molecules to
helium (He) atoms at the same temperature.
4.
Calculate the relative rate of diffusion of butane (C
4
H
10
) molecules
to carbon monoxide (CO) molecules.
5.
Calculate the relative rate of diffusion of oxygen (O
2
) molecules to
methane (CH
4
) molecules.
Lesson 8-7: Ideal Gas Law
One of the most useful gas laws is the Ideal Gas Law, which shows the
mathematical relationship between the pressure, volume, temperature, and
number of particles of a gas. The formula for the Ideal Gas Law is shown
here:
PV = nRT
where P = pressure; V = volume; n = number of moles;
T = temperature in Kelvin; and
R = the ideal gas law constant, 8.31 dm
3
× kPa/mol × K
