Perfect Gas Law

GENERAL GAS LAWS & FORMULAS
Perfect Gas Law: PV = nRT
P = Pressure in atmospheres
V = Volume in liters
R = Gas constant (0.0821 liter-atmospheres / K / mole)
T = Temperature in K
  If constant pressure V1/V2 = T1/T2
  If constant temperature P1/P2 = V2/V1
  If constant volume P1/P2 = T1/T2