Heats of Reaction: Enthalpy (6.2.1)

Question 1

What is Enthalpy?

Answer 1

• Enthalpy (H) is the internal energy (E) plus pressure multiplied by volume (PV). The change in enthalpy (∆H) equals the heat (qP) for a system at constant pressure.

Question 2

What is ∆H for positive and negative reactions?

Answer 2

• ∆H is negative for exothermic reactions, and positive for endothermic reactions.