Gay lussac’s law :
For a fixed amount of gas at constant volume, pressure of the gas is directly proportional to temperature of the gas on the absolute scale of temperature.
P∝Temperature(Absolute)
Absolute temperature is temperature in kelvin(K).
Experiment :
Cylinder filled with some gas heated constantly is covered with a piston from top.Pressure in the gas increases by the increase in temperature which is balanced by the weight added on the piston constantly by sprinkling sand such that the volume of the cylinder remains constant.In the process internal pressure of the gas increases at constant volume due to increase in temperature of the gas.
According to the Gay Lusssac’s law :
For a given amount of gas at constant volume :
P∝T
P=k3T,PT=k3(constant)
Here k3 depends on the amount of gas and volume of the gas.
For a given amount of gas at constant volume changes to a different pressure and temperature :
PiTi=PfTf
Where Pi and Ti are initial pressure and temperature and Pf and Tf are final pressure and temperature.