Answer:
Average molecular weight of air is 28.84 g/mol.
Explanation:
The average molecular weight of a mixture is determined from their molar composition and molecular weight.
Average molecular weight :[tex]\sum (\chi_i\times m_i)[/tex]
[tex]\chi_1[/tex] : mole fraction of the 'i' component.
[tex]m_i[/tex] = Molecular weight of i component
Average molecular weight of air with approximate molar composition of 79% nitrogen gas and 21% of oxygen gas can be calculated as:
Average molecular weight of air:
[tex]79\%\times 28 g/mol+21\%\times 32 g/mol[/tex]
[tex]=0.79\times 28 g/mol+0.21\times 32 g/mol=28.84 g/mol[/tex]
