Law of gaseous volumes or Gay-Lussac’s Law is that when gases combine together they do (1) In simple ratios by volume and (2) the volume of the product, if gaseous, also bears a simple relation to the volumes of the two reacting gases measured under the same conditions of temperature and pressure.
The Law of Chemical Combination are as follow: (1) The law of conservation of mass. (2) The law of constant or definite proportions. (3) The law of multiple proportions. (4) The law of reciprocal proportion. (5) The law of gaseous volumes.