State of Matter
Boyle's law
$$ P_{\,1}V_{\,1} = P_{\,2}V_{\,2} \text{ (at constant T and n)} $$
Charles' law
$$ \frac { V_{\,1}}{T_{\,1}} = \frac { V_{\,2}}{T_{\,2}} \text{ (at constant P and n)} $$
Avogadro's law
$$ V = kn \text{ (at constant T and P)} $$
Ideal gas equation
$$ PV = nRT $$
$$ M = \frac { dRT}{P} $$
Combined gas equation
$$ \frac { P_{\,1}V_{\,1}}{T_{\,1}} = \frac { P_{\,2}V_{\,2}}{T_{\,2}} $$
where n and R constant
Dalton's law of partial pressures
$$ P_{\,Total}= P_{\,1} + P_{\,2} + P_{\,3} + \cdots $$
Partial pressure in terms of mole fraction
$$ P_{\,i}= x_{\,i} P_{\,total} $$
Ven der Waals equation
$$ (P + \frac{an^{2}}{V^{2}})(V - nb) = nRT $$
Compressibility factor
$$ Z = \frac {PV}{RT} \text{ (for 1 mole of gas)}$$