Topic 3 - Particle Model of Matter - 3.2 - Internal Energy and Energy Transfers

Question 1

What is the internal energy of a
substance?

Answer 1

●The energy stored by the particles
●The sum of the total kinetic and potential energies that make up the system

Question 2

How does heating affect the energy of a
substance?

Answer 2

●Heating transfers energy to the substance
● It increases the energy of the particles that make up the substance

Question 3

What two things can heating a substance
do?

Answer 3

1. Raise its temperature
2. Change the state of the substance

Question 4

What three factors determine the
temperature change of a system?

Answer 4

1.Mass of substance being heated
2. Type of material (Specific heat capacity)
3. Energy inputted into the system

Question 5

State the equation used to calculate the temperature change when a substance is heated. Give appropriate units.

Answer 5

Question 6

Define specific heat capacity.

Answer 6

The amount of energy needed to increase the temperature of 1kg of a substance by 1°C.

Question 7

Describe how the internal energy and temperature of a substance changes when a change of state occurs.

Answer 7

●The internal energy of the substance will be increased or decreased
●The temperature of the substance will remain constant

Question 8

Define specific latent heat.

Answer 8

Question 9

State the equation for the energy required to change state. Give
appropriate units.

Answer 9

●Energy to change state = mass x specific latent heat

●Energy (J), Mass (kg), Specific latent heat (J/kg)

Question 10

What is the specific latent heat of fusion?

Answer 10

The energy required to change 1kg of a substance from solid state to liquid state without a change in temperature.

Question 11

What is the specific latent heat of
vaporisation?

Answer 11

The energy required to change 1kg of a substance from liquid state to gas state (vapour) without a change in temperature.