Question

A compound has an empirical formula C₂H4S.

What is its molecular formula, if its molar
mass is 168 g/mol?

Answer 1

• The atomic mass of carbon is 12.011 g/mol.
• The atomic mass of hydrogen is 1.00794 g/mol.
• The atomic mass of sulfur is 32.06 g/mol.

This means that the molar mass of
`\text{C}_(2)\text{H}_(4)\text{S}` is

`2(12.011)+4(1.00794)+32.06=60.11376`

Dividing this by the given molar mass, we get
`(168)/(60.11376) \approx 3`

So, the molecular formula is about
`\boxed{\text{C}_(6)\text{H}_(12)\text{S}_(3)}`