Question

6. What is the molecular formula of each of the compound with an empirical formula HCO2, and a

molar mass of 90.0 g/mol.

Answer 1

H₂C₂O₄

Step-by-step explanation:

The empirical formula is the simplest, whole number ratio of the atoms present in a molecule.

The molecular formula includes all the atoms present in a molecule.

The given formula, HCO₂, is the empirical formula. You can determine the molecular formula by calculating the molar mass of the empirical formula and comparing it to the molar mass of the actual molecule.

Atomic Mass (H): 1.008 g/mol

Atomic Mass (C): 12.011 g/mol

Atomic Mass (O): 15.999 g/mol

Molar Mass (HCO₂): 1.008 g/mol + 12.011 g/mol + 2(15.999 g/mol)

Molar Mass (HCO₂): 45.017 g/mol

Since the molar mass of the empirical formula is exactly half the molar mass of the molecular formula (90.0 / 45.017 = 2), each atom in the empirical formula must be multiplied by 2.

As such, the molecular formula is H₂C₂O₄.