Thermodynamics
Energy changes
$$ \Delta U = q_{\,v}, \Delta H = q_{\,p} $$
qv → Heat exchange at constant volume
qp → Heat exchange at constant pressure
Enthalpy
$$ H = U + pV $$
Relation between ΔH and ΔU
$$ \Delta H =\Delta U + p \Delta V \text{ or} $$
$$ \Delta H =\Delta U + ( \Delta n)RT $$
Heat Capacity
$$ C = \frac {q}{\Delta T} $$
$$ \text { Specific heat capacity } C_{\,s} = \frac {q}{m\Delta T} $$
$$ \text { Molar heat capacity } C_{\,n} = \frac {q}{n\Delta T} $$
First law of thermodynamics
$$ \Delta U = q + W $$
Enthalpy of reaction
$$ \Delta H = \sum \Delta H_{f^{O}} (product) - \sum \Delta H_{f^{O}} (reactants) $$