Question

What are empirical formulas?

Answer 1

The empirical formula is the lowest term ratio of the atoms found in a molecule.

An example would be the empirical formula for a carbohydrate is
`CH_2O`
one carbon for two hydrogens for one oxygen

The carbohydrate glucose has a formula of
`C_6H_12O_6`
Notice that the ratio is 1 C to 2 H to 1 O.

For the alkane group of hydrocarbons the molecular formulas are

Ethane `C_2H_6`
Propane `C_3H_8`
Butane `C_4H_10`

In each of these molecules the molecular formula can be determines from a base formula of
`C_nH_(2n+2)`
This is the empirical formula for all alkanes.

Here is a video which discusses how to calculate an empirical formula.

video from: Noel Pauller

I hope this was helpful.
SMARTERTEACHER