Internal Energy & Energy Transfers

Question 1

Internal Energy

Answer 1

Energy stored inside a system by the particles (atoms , molecules)
Internal energy is total kinetic energy & potential energy of all particles that make up a system
Heating changes the energy stored within the system by increasing the energy of the particles in system. Raises temperature of system or produces change of state.

Question 2

Specific Heat Capacity

Answer 2

If temperature of system increases, the increase in temperature depends on the mass of substance heated, type of material and the energy input to the system

Amount of energy required to raise the temperature of 1kg of a substance by 1 degree c
Delta E = m * c * delta theta

Question 3

Specific Latent Heat

Answer 3

The energy needed for a substance to change state is latent heat. When change of state occurs - energy supplied changes (breaks intermolecular bonds) energy stored (internal energy) but not temperature.

Amount of energy required to change the state of 1 kg of the substance without a change in temperature - E =mL
Specific latent heat of fusion – change of state from solid to liquid
Specific latent heat of vaporisation – change of state from liquid to gas

Question 4

Heating & Cooling Graphs