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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