What is the #"empirical formula"#?

1 Answer
Nov 11, 2015

Answer:

The empirical formula is the simplest whole number ratio that defines constituent atoms in a species. The molecular formula is always a multiple of the empirical formula.

Explanation:

Ordinarily you have to determine the empirical formula experimentally, (that's what #"empirical means"#, #"experimental"#), and from this empirical formula, the molecular formula is calculated. I will give you a few examples with this order reversed. The molecular formula of hydrogen peroxide is #H_2O_2#; its empirical formula is #OH#. The molecular formula of butane is #C_4H_10#; its empirical formula is #C_2H_5.# In both instances the empirical formula is the simplest whole number ratio that defines the proportion of the constituent atoms, as required. What are the empirical formulae of ethane, #C_2H_6#, hexane, #C_6H_14#, octane, #C_8H_18#, and ethanol, #C_2H_5OH#?

There are many other answers on Socratic that show how the empirical formula may be calculated by means of a protocol with specific problems quoted and solved. I urge you to search them out.