Question

What is the empirical formula of ethylene glycol?

Answer 1

The molecular formula of ethylene glycol is `HOCH_2CH_2OH`, i.e. `C_2H_6O_2`. The empirical formula is `??`

Explanation:

The empirical formula is the simplest whole number ratio defining constituent atoms in a species (this is glib, I think I learned this definition when I was 15, and it has stuck!). Given this, the molecular formula is clearly not the empirical formula (why not?), but is a multiple of the empirical formula.

So the empirical formula of ethylene glycol is `CH_3O`; this is the ratio of carbons to hydrogen to oxygen we would find if we tried to determine the composition of the stuff by experiment (i.e. empirically).