Chapter 8 The Gas Phase

Question 1

What are the units of gas pressure?

Answer 1

1 atm = 760 mmHg = 760 Torr = 101.325 kPa

Question 2

What is the ideal gas law?

Answer 2

PV = nRT

P - Pressure
V - Volume
n - number of moles
R - Ideal gas constant
T - Temperature

Question 3

At STP how many L does one mole occupy?

Answer 3

22.4 L

Question 4

What is Avogadro’s law?

Answer 4

Isothermal and isobaric conditions

V & n are directly proportional

Question 5

What is Boyle’s Law?

Answer 5

P1V1 = P2V2
Isothermal Conditions

Inverse relationship between the pressure and volume of a gas

Question 6

What is Charles Law?

Answer 6

V1/T1 = V2/T2
Isobaric Conditions

Direct relationship between the volume and temperature.

Question 7

What is Gay-Lussac’s Law?

Answer 7

P1/T1 = P2/T2
Isochoric Process

Direct relationship between the pressure and temperature of a gas

Question 8

What is the combined gas law?

Answer 8

Volume is seen to be inversely proportional to pressure, directly proportional to the temperature and directly proportional to the number of moles of gas.

P1V1/n1T1 = P2V2/n2T2
Breaks down to PV = nRT

Question 9

What is Dalton’s Law of Partial Pressure?

Answer 9

Total pressure = sum of the individual pressures

Under isothermal and isochoric conditions
P is proportional to n

Question 10

What is Henry’s Law?

Answer 10

The solubility of a gas will increase with increasing partial pressure of the gas.

Question 11

What is Kinetic Molecular Theory?

Answer 11

Explanation for behavior of gases.

• Composed of particles
• In constant, random motion
• Move in ‘straight lines
• Very far apart
  *Temp. propor. to Avg. K energy
  *Collisions elastic
• Move independently

Question 12

What is Graham’s law?

Answer 12

Gases with lower molar masses will diffuse or effuse faster than gases with higher molar masses at the same temperature.

Question 13

What is Diffusion?

Answer 13

spreading out of particles from high to low concentration due to driving force

Question 14

What is Effusion?

Answer 14

Gas movement through a small hole under pressure

Question 15

When do real gases deviate from ideal behavior?

Answer 15

Under high pressure (low volume) and low temperature
conditions.

Question 16

How do real gases deviate from ideal behavior?

Answer 16

• Occupy less volume than predicted by the ideal gas law because the particles have intermolecular attractions.
• Occupy more
  volume than predicted by the ideal gas law because the particles occupy physical space.

Question 17

What is van der Waals equation of state?

Answer 17

Correct the ideal gas law for intermolecular attractions (a) and molecular volume (b).

[P+ n^2a/V^2] (V-nb) = nRT