Question

What are the charges of the anion in each of the following compounds: CaO, Na₂SO₄, KClO₄, Fe(NO₃)₂, Cr(OH)₃?

Answer 1

The anions in the compounds CaO, Na₂SO₄, KClO₄, Fe(NO₃)₂, and Cr(OH)₃ are O2-, SO42-, ClO4-, NO3-, and OH- respectively.

Step-by-step explanation:

To determine what are the charges of the anion in the given compounds, we examine the charge balance in each compound, knowing that the total positive charge must equal the total negative charge to maintain electrical neutrality.

1. For CaO (calcium oxide), the calcium ion (Ca2+) balances with the oxide anion, O2-.
2. In Na₂SO₄ (sodium sulfate), the sulfate anion is SO42- as there are two sodium ions each with a charge of 1+ to balance out the charge.
3. For KClO₄ (potassium perchlorate), the perchlorate anion is ClO4-.
4. Fe(NO₃)₂ (iron(II) nitrate) has the nitrate anion NO3-, with two of these needed to balance one Fe2+ ion.
5. Lastly, Cr(OH)₃ (chromium(III) hydroxide) contains the hydroxide anion OH-, with three of these anions balancing one Cr3+ ion.