Determining the molecular formula of a hydrocarbon with a relative molecular mass of 54​

C₄H₆

Explanation:

A hydrocarbon is a molecule that only contains atoms of Carbon and Hydrogen. As you remember, the molar mass of Carbon is 12g/mol and the molar mass of Hydrogen is 1g/mol.

To solve this question we can find the amount of Carbons necessary that doesn't exceed the 54g/mol. That is:

54g/mol / 12g/mol = 4.5

As the molecular formula must be given in whole numbers, the amount of Carbons is 4. This 4 carbons have a mass of:

12g/mol*4 = 48g/mol

And the hydrogens necessaries to suply the molecular mass are:

54 - 48 = 6 hydrogens

That means molecular formula is: