Write a formula for each ionic compound. (a) copper(I) chlorate (b) potassium permanganate (c) lead(II) chromate (d) calcium fluoride (e) iron(II) phosphate (f) lithium hydrogen sulfite
The Correct Answer and Explanation is:
Here’s a breakdown of the formulas for each ionic compound:
(a) Copper(I) Chlorate
- Copper(I) refers to copper with a +1 charge.
- Chlorate is the ion ClO3−\text{ClO}_3^-ClO3−, with a -1 charge.
Since the charges of copper(I) and chlorate are both 1, the formula is simple: - Formula: CuClO3\text{CuClO}_3CuClO3
(b) Potassium Permanganate
- Potassium has a +1 charge (K+\text{K}^+K+).
- Permanganate is the ion MnO4−\text{MnO}_4^-MnO4−, with a -1 charge.
Since the charges are equal, the formula is: - Formula: KMnO4\text{KMnO}_4KMnO4
(c) Lead(II) Chromate
- Lead(II) has a +2 charge (Pb2+\text{Pb}^{2+}Pb2+).
- Chromate is the ion CrO42−\text{CrO}_4^{2-}CrO42−, with a -2 charge.
Again, since the charges are equal, the formula is: - Formula: PbCrO4\text{PbCrO}_4PbCrO4
(d) Calcium Fluoride
- Calcium has a +2 charge (Ca2+\text{Ca}^{2+}Ca2+).
- Fluoride is the ion F−\text{F}^-F−, with a -1 charge.
To balance the charges, we need two fluoride ions for every calcium ion: - Formula: CaF2\text{CaF}_2CaF2
(e) Iron(II) Phosphate
- Iron(II) has a +2 charge (Fe2+\text{Fe}^{2+}Fe2+).
- Phosphate is the ion PO43−\text{PO}_4^{3-}PO43−, with a -3 charge.
To balance the charges, we need three iron(II) ions for every two phosphate ions: - Formula: Fe3(PO4)2\text{Fe}_3(\text{PO}_4)_2Fe3(PO4)2
(f) Lithium Hydrogen Sulfite
- Lithium has a +1 charge (Li+\text{Li}^+Li+).
- Hydrogen sulfite is the ion HSO3−\text{HSO}_3^-HSO3−, with a -1 charge.
Since the charges are equal, the formula is: - Formula: LiHSO3\text{LiHSO}_3LiHSO3
Explanation:
To write the formulas for ionic compounds, we need to balance the charges between the positive ions (cations) and the negative ions (anions). The charge on each ion can usually be determined based on the group number in the periodic table, with a few exceptions for transition metals and polyatomic ions. The total positive charge must balance the total negative charge in the compound, and we achieve this balance by adjusting the number of ions in the formula. The result is a neutral compound with no net charge
