ΔH°

Definition

ΔH°, or standard enthalpy change, is the amount of heat absorbed or released in a reaction at constant pressure and standard conditions (1 atm pressure and 298.15 K).

Related terms

Enthalpy (H): The total heat content of a system at constant pressure.

Exothermic Reaction:

A chemical reaction that releases heat to its surroundings (ΔH is negative).

Endothermic Reaction:

A chemical reaction that absorbs heat from its surroundings (ΔH is positive).