Thermochemistry vocab

Thermochemistry

The study of how heat is absorbed or evolved during physical and chemical reactions.

Temperature

A measure of the average kinetic energy of the particles within a system.

Heat (q)

The flow of thermal energy between objects of different temperatures, moving from hot to cold.

Endothermic

A process or reaction in which heat is absorbed from the surroundings.

Exothermic

A process or reaction in which heat is released into the surroundings.

Enthalpy Change (ΔH)

The total change in thermal energy during a chemical reaction.

Thermochemical Equation

A balanced chemical equation that includes the amount of heat energy absorbed or released.

Melting

An endothermic phase change where a solid becomes a liquid.

Freezing

An exothermic phase change where a liquid becomes a solid.

Vaporization (Boiling)

An endothermic phase change where a liquid becomes a gas.

Condensation

An exothermic phase change where a gas becomes a liquid.

Sublimation

An endothermic phase change where a solid turns directly into a gas.

Deposition

An exothermic phase change where a gas turns directly into a solid.

Specific Heat Capacity (C)

The quantity of heat energy needed to change the temperature of one gram of a substance by one degree.

Formula

$q = mC\Delta T$

q

Heat energy gained or lost in Joules (J).

m

Mass of the substance in grams (g).

C

Specific heat capacity (J/g°C).

ΔT

Change in temperature (Final - Initial).