Question

Consider the ionic compound that is the combination of the Chromium (III) and hydroxide ions. How many chromium atoms would be present in this compound?

Answer 1

An ionic compound forms when a metal bonds with a non-metallic element. Metals usually form the cation and non-metal anions. Chromium has an oxidation number of +3 in the compound and charge on hydroxide ion is -1.

Cation here is $Cr^{3+}$

Anion is the hydroxide ion $OH^{-}$

So the formula of the compound will be: $Cr(OH)_{3}$. The compound has one chromium atom and two hydroxide ions.

Therefore, there will be one Chromium atom per each chromium hydroxide compound.