Kinetic theory of Gases

Question 1

How do molecules move in gases?

Answer 1

in a straight line of motion

Question 2

What are 5 properties of the molecules in gases

Answer 2

-average distance between each molecule is large (no volume but have mass)
-negligible/small intermolecular forces
-all collisions between the molecules are elastic i.e. no net energy loss
-pressure is due to molecule collisions with container wall
-average Ke of molecule increases as temp increases

Question 3

What is the temperature in gas?

Answer 3

A measure of the average kinetic energy (Ke) of any gas

Question 4

What is the relationships between mass and speed with temperature in gas?
*Practice drawing graph for vary in temp of particles

Answer 4

Mass increase will decrease speed (Ke decrease) but same temperature
If temperature changes so does the speed (increase Ke) but mass stays same

Question 5

What is diffusion in gases?

Answer 5

Gases in mixture spreading out uniformly to fill total volume available

Question 6

What effects rate of diffusion?

Answer 6

-temperature
-molar mass
-average velocity

Question 7

Relationships between gas volume and container volume

Answer 7

they are equal

Question 8

Convert 1ml to cm3

Answer 8

1ml=1cm3

Question 9

What is pressure in gases?

Answer 9

Force exerted on area of a surface by particles of gas as they collide with the containers surface.

Question 10

What happens when a gas is compressed?

Answer 10

Increase in collision
Increase force on the surface
Increase in force per unit surface=pressure

Question 11

What is partial pressure in gases?

Answer 11

Gaseous mixtures=air pressure is a sum of all individual pressures of gases in the mixture
-the individual gas pressure is called partial pressure

Question 12

What is absolute temperature scale?

Answer 12

A measure of average kinetic energy of molecules

Question 13

What is the relationship between volume and temperature?

Answer 13

There is a lower limit to temperature
e.g.
Celsius temp +273 = absolute temp
absolute temp -273 =Celsius temp

Question 14

What is Avogadro’s hypothesis?

Answer 14

Equal volume of all gases measured at STP, will contain equal number of particles.
Thus, no matter type of gas, total number of particles is same under the same conditions.

Question 15

What is Boyles law? What comes from volume reduction

Answer 15

If temp of gas is kept constant, volume is inversely proportional to pressure
i.e. pressure increase=volume decrease

vol. reduction= greater number of molecules per unit volume
thus particles collide more
which means pressure will increase

Question 16

What is Charles Law?

Answer 16

Constant pressure means that volume is directionally proportional to temperature
-rise in temp=increase speed + kinetic energy
-particles therefore collide with container walls more= constant pressure if vol. increases