Enthalpy and Thermochemistry

Measuring the heat absorbed or released during chemical and physical changes.

Enthalpy

Enthalpy (H) is a measure of the total heat content of a system at constant pressure.

  • Exothermic reaction — releases heat (ΔH is negative)
  • Endothermic reaction — absorbs heat (ΔH is positive)

Hess's Law

The total enthalpy change for a reaction is the same, regardless of the number of steps taken to complete it.

Lesson 13 of 26
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