# What is the name of the ionic compound Na3AlF6?

May 14, 2014

The name of ${\text{Na"_3"AlF}}_{6}$ is sodium hexafluoridoaluminate.
common name is Cryolite

#### Explanation:

The name of an ionic compound is

name of cation + name of anion

Cations of metals in Groups 1 and 2 have the same name as the metal (e.g., sodium or magnesium).

In this case, the name of the cation is sodium.

The ${\text{AlF}}_{6}^{3 -}$ ion is a complex ion. The name of the anion ends in "-ate".

The fluorine atoms are ligands.

The names of negative ligands end in "-o". Thus, the name of the fluoride ion becomes "fluorido" when it is a ligand.

We use the multiplying prefix "hexa-" to show six fluoride ions.

The name of the ${\text{AlF}}_{6}^{3 -}$ ion is hexafluoridoaluminate.

So the official name of ${\text{Na"_3"AlF}}_{6}$ is sodium hexafluoridoaluminate.

The older name was sodium hexafluoroaluminate(III).