Gay-Lussac's Law
Gay-Lussac's Law which is most often
referred to as the Pressure law, was founded by a French Chemist &
Professor Joseph Louis Gay-Lussac in 1809.
Gay-Lussac's Law has also been referred
to as Charle's Law, but they are not the same.
Gay- Lussacs Law gives the relationship
between pressure and temperature when volume and amount are held constant.
Gay-Lussac found that for a gas, if the
pressure increases, the temperature increases, and if the temperature
decreases, the pressure decreases. Based on this Gay-Lussac stated his law as
" The Pressure of a fixed amount of Gas at a fixed Volume is DIRECTLY proportional
to its Temperature ".
Mathematically the Law can be stated as :-
P α T or P = k T or P/T = k
Where,
P is the pressure of the gas in
atmospheres,
T is the temperature of the gas in
Kelvin &
k is a constant .
Consider,
If P1 and T1 is
the initial pressure and temperature of a gas,
Then according to Gay-Lussac's Law :
P1 / T1 = constant
After the change in pressure and temperature,
P2 / T2 = constant
Combining the two equations we get :
P1 / T1 = P2
/ T2
This law holds true because Temperature is a measure of the Average Kinetic Energy of a substance and as the Kinetic Energy of a Gas increases, it's particles collides with the walls of the container more rapidly, thereby exerting an increased Pressure.
Thus from the Gay-Lussac’s law we can
say that it may be dangerous to heat a gas in a closed container because the
increased pressure might cause the container to explode.