Particle Motion in Gases

Question 1

State what causes pressure in gases.

Answer 1

Particles in the gas colliding with a surface cause a force and so a pressure

Question 2

What temperature on the Celsius scale is known as absolute zero?

Answer 2

-273°C

Question 3

What is 300 K in degrees Celsius?

Answer 3

27°C

To convert from kelvins to degrees Celsius, you need to subtract 273 from the temperature in kelvins. 300 - 273 = 27°C

Question 4

True of false? The particles of a substance cooled below absolute zero have very little energy in their kinetic stores.

Answer 4

False.
Absolute zero is the coldest anything can get, because the particles have as little energy in their kinetic stores as it’s possible to have, so you can’t cool a substance further.

Question 5

If the temperature of a gas increases, how does the motion of its particles change?

Answer 5

The average speed of the particles increases

Question 6

A gas is held in a container with a constant volume. Why will the gas pressure increase if it is heated?

Answer 6

Heating the gas will mean that, on average, the particles will move faster and collide with the walls of the container more often and with more force. This will increase the total force exerted on the walls and so increase the pressure.