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AVOGADRO'S LAW OF GAS

 A mole of a substance has a mass numerically equal to the molecular weight of  the substance. 

 One g mol of oxygen has a mass of 32g, 1kg mol of oxygen has a mass of  32kg, 1kg mol of nitrogen has   a mass of 28 kg and so on,.

 Avagadro's law states that the volume of  a g mol of all gases at the pressure of 760 mm Hg and Temperature of 0*C is the same, and is equal to 22.4 litres. Therefore, 1g mol of a gas has a volume of 22.4 * 10^3 cm3 and 1 kg mol of a gas has a volume of 22.4 m3 at normal temperature and pressure (N.T.P).




For a certain gas, if m is its mass in kg, and u its molecular weight, then the number of  kg moles of the gas, n, would be given by 

n= m kg  / (u ( kg / kg mol ))  =  m / u   kg moles

The molar volume, v*, is given by 

v* = V/n (m3/kg mol)

Where V is the total volume of  the gas in m3 .  

 

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