Question

What is the molecular formula of a compound with the empirical formula NO2 and a molar mass of 138.02 grams per mole

Answer 1

Molar mass of N = 14 g/mol

Molar mass of O2 = 32 g/mol

Adding both masses = 46 g/mol

Actual molar mass/ Empirical molar mass = 138.02 / 46 = 3

Now multiplying this co effecient with empirical fomula NO2 = 3(NO2)

= N3O6

So according to above explanation,

D) N3O6, is the correct answer.

Answer 2

The total mass of the empirical formula, NO2, is 46 grams per mole. To determine the molecular formula, divide the molar mass of the substance by 46 grams per mole. This is shown below,

(138.02 / 46) = 3

Multiply the subscripts of the empirical formula by the calculated quotient. Thus, the empirical formula is N3O6.