What does the empirical formula indicate?

1 Answer

Empirical formulas provide the lowest whole number ratio of elements present in a compound.

Formulas for ionic compounds are always empirical formulas.

Examples:
NaCl is a 1:1 ratio of sodium and chloride ions
#CaF_2# is a 1:2 ratio of calcium and fluoride ions
#Al_2O_3# is a 2:3 ratio of aluminum and oxide ions

Empirical fomulas also can be written for molecular compounds (covalent Bonding)

Examples:
Hydrogen peroxide (#H_2O_2#) has an empirical formula of #HO#.
Glucose (#C_6H_12O_6#) has an empirical formula of #CH_2O#.
Sucrose (#C_12H_22O_11#) has the same empirical formula as its molecular formula

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

Simple explanation, nice looking website https://www.chem.wisc.edu/deptfiles/genchem/sstutorial/Text6/Tx65/tx65.html