First of all we should find out the mass of 1 mole of nitrogen molecules `(N_(2))`. Now,
`1` mole of `N_(2)` = Molecular mass of `N_(2)` in grams
`=` Mass of 2 N atoms in grams
`= 2 xx 14`
`= 28` grams
Thus, the mass of 1 mole of nitrogen molecules is `28` grams. Now, `1` mole of nitrogen molecules contains `6.022 xx 10^(23)` molecules. This mass of `3.011 xx 10^(24)` molecules of nitrogen is `140` grams.
