Question

In what smallest whole-number ratio must N and O atoms combine to make dinitrogen to tetroxide $N_{2}O_{4}$? What is the mole ratio of the elements in this compound?

Answer 1

Through the Empirical formula, we can find out the smallest whole number ratio which exists between the elements.

Empirical formula and the molecular formula are mathematically related  

                  Molecular formula = n x empirical formula

The molecular formula weight of dinitrogen tetroxide  $N_2 O_4$ is 92 g/mol.

To get the molar mass, use the molar masses of the individual atoms of Nitrogen and Oxygen

Molar mass of Nitrogen is 14.007 g/mol (Since it has one atom)

Molar mass of Oxygen is  2 × 15.9994 g/mol= 32g/mol (Since it has two atoms)

Thus, Empirical formula weight = 14 + 32 = 46g/mol

Molecular formula weight = n x empirical formula weight

                            46g/mol  = n x 92 g/mol

Therefore, n = 2 which is the mole ratio of elements in this compound.

The molecular formula for your compound is

             $2NO_2$=$N_2 O_4$ → dinitrogen tetroxide.

Answer 2

The mole ratio of the element is "2".

Explanation:

As we know that:

• Molecular formula = n x empirical formula
• Molecular formula of N2O4 = 92 g/mol.
• Molar mass of Nitrogen = 14.007 g / mol
• Molar mass of Oxygen = 2 × 15.9994 g / mol = 32 g/mol
• Empirical formula weight = 14 + 32 = 46 g/ mol

Molecular formula weight = n x empirical formula weight

                           46 g / mol  = n x 92 g / mol

The mole ratio of element "n" = 2

Molecular formula of compound = N2O4