Internal Energy and Energy Transfers - Paper 1

Question 1

Define internal energy

Answer 1

The internal energy of a system is the total energy (kinetic and chemical potential) of the particles that make up the system.

Question 2

Explain the effect of heating a system.

Answer 2

Heating a system increases the internal energy.
Increasing kinetic energy increases the system’s temperature.
Increasing chemical potential energy produces a change of state.

Question 3

Define specific heat capacity

Answer 3

The specific heat capacity of a substance is the amount of energy required to raise the temperature of one kilogram of the substance by one degree Celsius.

Question 4

Define specific latent heat

Answer 4

The specific latent heat of a substance is the amount of energy required to change the state of one kilogram of the substance with no change in temperature.

Question 5

Explain the different specific latent heat values.

Answer 5

Specific latent heat of fusion applies for a change of state from solid to liquid.
Specific latent heat of vaporisation applies for a change of state from liquid to vapour.