Thermal properties of matter

Internal energy

• Internal energy consists of the kinetic energy associated with the random motion of the particles and the total potential energy between particles in the system

Heat capacity

• Heat capacity of an object is the change of its internal energy per unit change in temperature

• Heat capacity is the amount of thermal energy required to raise the temperature of a substance by 1 K.

• c = q/changeintemp

Specific heat capacity

• Specific heat capacity of a material is the change of its internal energy per unit change in mass for each unit change of temperature

• Specific heat capacity is defined as the amount of thermal energy required to raise the temperature of a unit mass (1 kg) of a substance by 1 K.

• c = q/mchangeinheat

Latent heat

• Latent heat is the energy released or absorbed to change the state of a substance at constant temperature

Latent heat of fusion

• Latent heat of fusion is the amount of energy transferred to change a substance between solid and liquid states at constant temperature

• Q = ml

Latent heat of vaporisation

• Latent heat of vaporisation is the amount of energy transferred to change a substance between liquid and gas states at constant temperature

Specific latent heat

Amount of energy transferred per unit mass of a substance to change it between —— state at constant temperature

Internal energy

• The internal energy of a substance increases when it is heated

• The internal energy of a substance decreases when it is cooled