Easy Practice — Set 2

Quick Recap — Hess's Law & Thermochemistry

• Hess's law: the total enthalpy change is the same by any route (because $H$ is a state function); thermochemical equations can be added.
• $\Delta H=\Delta U+\Delta n_g RT$ ($\Delta n_g=$ moles of gaseous products $-$ reactants).
• For ideal gas: $C_p-C_v=R$.
• Enthalpy of reaction $=\sum\Delta H_f^\circ(\text{products})-\sum\Delta H_f^\circ(\text{reactants})$. Neutralisation of a strong acid by a strong base $\approx-57.1$ kJ/mol.