Equal volumes of gases under identical temperature and pressure conditions will contain equal numbers of particles (atoms, ion, molecules, electrons, etc.).

Avogadro's Number= 6.02 ^.10²³ atoms in a mole 

 At constant temperature, the volume of a confined gas is inversely proportional to the pressure to which it is subjected.

Formula: PV=k or P₁V₁=P₂V₂ or P₁/P₂=V₁/V₂ (P=pressure; V=volume)

At constant pressure, the volume of a confined gas is directly proportional to the absolute temperature.

Formula: V=kT or V₁/V₂=T_1/T₂ (V= volume;T=temperature) 

The pressure of a mixture of gases is equal to the sum of the partial pressures of the component gases.

Pressure_Total=Pressure₁+Presssure₂+...Pressure_n

This law is about how pressure and temperature relate, which means the law assumes a constant volume of gas (meaning we assume the volume is not variable—it does not change). This law says that pressure is directly proportional to temperature.

Formula:  P1/P2=T₁/T₂

The state of an ideal gas is determined by its pressure, volume, and temperature.

Formula:  PV=nRT

where: P is the absolute pressure

               V is the volume of the vessel
                    n is the number of moles of gas
            R is the ideal gas constant
                 T is the absolute temperature

The solubility of a gas (unless it is highly soluble) is directly proportional to the pressure applied to the gas.

Formula:  C=k*P_gas

where: C is the solubility of a gas at a fixed temperature in a particular solvent(M or ml gas/L)

k= Henry's law constant(M/atm)

P_gas=Partial pressure of the gas(atm)