14.3 Specific heat capacity and specific latent heat

Specific heat capacity c is energy required to raise 1 kg of a substance by 1 K: ∆E=mc∆T.

Use temperature difference, not absolute temperature, and distinguish the substance mass from container or heater losses.

Heating 2.0 kg of water by 5 K requires about 42 kJ if c=4200 J kg⁻¹ K⁻¹.

A high specific heat capacity means more energy per kilogram per degree, not that the object always reaches a higher final temperature.

Specific latent heat L is energy required per kilogram to change state at constant temperature: E=mL. Fusion melts solid to liquid; vaporisation changes liquid to gas.

During the phase change, energy changes intermolecular potential-energy store rather than raising temperature.

Melting 0.20 kg of ice at its melting point requires E=mL_f, while its temperature remains constant during the melt.

Latent heat is not “hidden temperature”; it is energy transferred during a state change, and fusion/vaporisation have different values.