Chapter 10 - Properties Of Gases

Question 1

Gas

Answer 1

A substance that has no well-defines boundaries but diffusés rapidly to fill any container in which it is placed

Question 2

Which diffusés quicker between ammonia and hydrogen chloride

Answer 2

Lighter ammonia molecules diffuse quicker than heavier hydrogen chloride molecules

Question 3

Properties of Gases

Answer 3

No fixed volume - take volume of container

Volume depends on temperature and pressure

Question 4

Temperature

Answer 4

Measure of the degree of hotness of an object

Question 5

0°C is equal to

Answer 5

273K

Question 6

Pressure of a gas

Answer 6

The force the gas exerts on a unit area

Newtons per metre squared or pascals

Question 7

1kPa is equal to

Answer 7

1000 Pa

Question 8

Normal atmospheric pressure

Answer 8

100kPa

100,000 Pa

Question 9

1 litre is equal to

Answer 9

1000cm^3

Question 10

Standard Temperature

Answer 10

273K

0°C ~ freezing point

Question 11

Standard pressure

Answer 11

100,000 Pa

100 kPa

Question 12

Boyle’s Law

Answer 12

At constant temperature, the volume of a fixed mass of gas is inversely proportional to its pressure

pV=k

Question 13

Charles’ Law

Answer 13

At constant pressure, the volume of a fixed mass of gas is directly proportional to its temperature measured on the Kelvin Scale

k = V/T

Question 14

Combined Gas Law

Answer 14

p1V1 = p2V2
–––– –––––
T1 T2

• Convert to Kelvin
• Consistent units

Question 15

Gay-Lussac’s Law of Combining Volumes

Answer 15

In a reaction between gases,
The ratio between the volumes of the reactant gases
and the gaseous products
can be expressed in simple whole numbers
Provided the volumes are measured at the same temperature and pressure

Question 16

Avogadro’s Law

Answer 16

Equal volumes of gases contain equal numbers of molecules under the conditions of temperature and pressure

Question 17

One mole of a gas occupies

Answer 17

22.4L

Question 18

Assumptions of the Kinetic Theory of Gases

Answer 18

• Gases are made up of particles in continuous rapid, random motion
• No attractive or repulsive forces between the molecules of a gas
• Gas molecules are so small and widely separated that the volume of all the molecules is tiny compared to the spec they occupy
• The collisions are perfectly elastic
• Average kinetic energy of molecules is proportional to temperature on Kelvin scale

Question 19

Limitations of the Kinetic Theory of Gases

Answer 19

• All real gases DO have tiny attractive forces between the molecules .e.g. ammonia
• Under high pressure when molecules are crowded together, the volume is not tiny compared to the distance between them

Question 20

Ideal gas

Answer 20

One that perfectly obeys all the assumptions of the kinetic theory of gases under all conditions of temperature and pressure

Question 21

Real gases

Answer 21

Forces of attraction and repulsion do exist between the molecules

The volume of the molecules is not negligible

Question 22

Rapid movement of tiny particles in a liquid or gas

Answer 22

Brownian motion

Question 23

When do gases depart from ideal behavior

Answer 23

High pressure and low temperatures, molecules are close together and moving slowly