Particle Model of Matter - Heating and Cooling Graphs, Specific Latent Heat and Particle Motion in Gases

Question 1

How do heating graphs work?
(Model answer)

Answer 1

As a substance is heated up, the temperature rises, which increases the energy in the particles. At a certain point, the temperature will stop increasing. This means that it has reached the melting point and latent heat is weakening the bonds between particles. While the temperature wont increase, the internal energy store does. The temperature begins to increase once all of the substance is liquid. The same thing happens when it begins to boil and the opposite happens for condensing and freezing.

Question 2

Define Specific Latent Heat

Answer 2

Specific Latent Heat is the amount of enregy required to change the state of 1kg of a substance without a change in temperature.

Question 3

Define Specific Latent Heat of Fusion and Vaporisation

Answer 3

• Specific Latent Heat of Fusion is the amount of energy required to change 1kg of a substance from solid to liquid without a change in temperature
• Specific Latent Heat of Vaporisation is the amount of energy required to change 1kg of a substance from liquid to gas without a change in temperature

Question 4

What causes pressure in gas?

Answer 4

Pressure in gas is caused due to the collisions made by particles against the wall of the container that they’re in