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1.2.1.9 Avogadro’s Law
Avogadro’s law states that under the same conditions of pressure and temperature,
equal volumes of different gases have an equal number of molecules.
Mathematically, this law is written as:
V
n
V
n
1
1
2
2
=
Where
n 1  = number of molecules in gas with volume V 1 .
n 2  = number of molecules in gas with volume V 2
1.2.1.10 Combined Gas Laws
The combined gas law is obtained by combining the relationship between the pressure, volume, and temperature for a fixed quantity of gas, written as:
p V
T
p V
T
1 1
1
2 2
2
=
1.2.1.11 Ideal Gas Law
By the addition of Avogadro’s law, the combined gas law develops into the ideal
gas law:
pV nRT
=
Where
p = pressure of gas.
V = volume of gas.
n = the number of moles.
R = the universal gas constant (value of 0.08206 [atm∙ L/mol∙K]).
T = absolute temperature (K).
An equivalent formulation of this law is:
pV kNT
=
Where
p = the pressure of gas.
1.2 General Chemistry