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Calculate the average molecular weight of air (1) from its approximate molar composition of 79% N2, 21% 02x

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Answer:

Average molecular weight of air is 28.84 g/mol.

Step-by-step explanation:

The average molecular weight of a mixture is determined from their molar composition and molecular weight.

Average molecular weight :
\sum (\chi_i* m_i)


\chi_1 : mole fraction of the 'i' component.


m_i = 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:


79\%* 28 g/mol+21\%* 32 g/mol


=0.79* 28 g/mol+0.21* 32 g/mol=28.84 g/mol

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