BOYLE'S LAW
The pressure of a given mass of a gas varies inverslyas its volume at constant Temp.

CHARLE'S LAW
The vol. of a given mass of a gas increases or decreases by 1/ 273.15 of its vol. at 0°c for every degree rise or fall of temp. at Constant pressure

GAY LUSSAC'S LAW
At constant vol. pressure of a given mass of a gas varies directly with the temprature.

AVAGADRO'S LAW
At const. temp. and pressure equal volumes of all gases contain equal no. of molecules.