Question

A molecular compound is found to consist of30.4% nitrogen and 69.6% oxygen. Ifthe molecule contains 2 atoms of nitrogen, what is the molar mass of the molecule

Answer 1

Answer:

92.01 g/mol

Explanation:

So first you need to find the empirical formula by the percents. That would be, assuming that you have 100 grams of the the sample, divide each quantity of each element found by its respective molar mass.

30.4 g of N ÷ 14 g/mol N= 2.17 mol of N

69.6 g of O ÷ 16g/mol= 4.35 mol of O

You can establish now the empirical formula.

N2.17O4.35,

but since you can't have a decimal subscript, you divide each subscript by the minimum subscript

NO2

So then you're said that the molecular formula derived from that empirical formula has 2 nitrogen, so you multiply all the subscripts, by 2:

N2O4

-Dinitrogen Tetraoxide

-Nitrogen oxide (IV)

Then all you have to do is find the molecular mass of the compound using the periodic table and what you obtain is the molar mass.

remember: molecular mass is correspondent to molar mass.