Identify the ions in the compounds represented in the following formulas. Click in the answer box to open the symbol palette. Cation Formula Anion Formula
a) NaBr
b) AlCI3
c) Ba3(PO42
d) Mn(NO3)2

Answer and Explanation:

A ionic compound can be dissociated into its ions: cations (with positive charge) and anions (with negative charge). The net charge of the compound is zero, so the sum of the charges of the ions must be zero.

We can see the ions in the compounds from the dissociation equilibrium, as follows:

a) NaBr  ⇒ Na⁺ + Br⁻

Cation: Na⁺

Anion: Br⁻ (bromide)

b) AlCI₃ ⇒ Al³⁺ + 3 Cl⁻

Cation: Al³⁺

Anion: Cl⁻ (chloride)

c) Ba₃(PO₄)₂⇒ 3 Ba²⁺ + 2 PO₄³⁻

Cation: Ba²⁺

Anion: PO₄³⁻ (phosphate)

d) Mn(NO₃)₂ ⇒ Mn²⁺ + 2 NO₃⁻

Cation: Mn²⁺

Anion: NO₃⁻ (nitrate)