A Nitrogen and Oxygen compound contains 4.2 g of Nitrogen and 12 g of Oxygen. Find the empirical formula. If the molar mass is 756 g per mol, what is the molecular formula?

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A compound of nitrogen and oxygen has 4.2 g of nitrogen and 12 g of oxygen.

As the molar mass of nitrogen is 14 and that of oxygen is 16, the ratio of the number of moles of nitrogen and oxygen in the compound is 1 : 2.5. Multiplying the two by two to yield whole numbers for both gives an empirical formula of 2: 5.

The empirical formula of the compound is N2O5. The molecular mass pf the compound is 756 g/mole. The mass of the empirical formula is 108. This gives a molecular formula of N14O35

The molecular formula of the compound is N14O35.

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