V ∝ n
V = kn
• This law states that equal volumes of all gases under similar conditions of temperature and pressure contain equal number of molecules.
• No. of molecules in one mole of a gas = 6.022 x 1023 = NA (Avogadro constant).
• Molar Volume – Volume occupied by one mole of each substance.
• It contains the same number of molecules i.e. NA .
Molar Volume at different T and P are as follows :
• STP : Standard Temperature and Pressure
• NTP : Normal Temperature and Pressure
• SATP : Standard Ambient Temperature and Pressure
No. of moles, n = \(\frac{N}{N_A}\) (N = no. of molecules)
where, d = density of the gas
⇒density of a gas ∝ molar mass (M)
Ideal gas equation or Equation of State
- It describes the state of any gas
- Combine Boyle's law, Charles' law and Avogadro's law
V \(\propto \frac{1}{P}\)(at constant T & n) Boyle's Law
V ∝ T(at constant p& n) Charles Law
V ∝ n (at constant T& P) Avogadro's Law
It is the approximate equation of state of any gas and becomes increasingly exact as pressure of the gas approaches zero.
R = Universal Gas Constant.
