Nomenclature Worksheet 3: Ionic Compounds Containing Polyatomic Ions, displaying a table for naming and writing formulas of ionic compounds with polyatomic ions.

Let's solve this Nomenclature Worksheet step by step. We are dealing with ionic compounds containing polyatomic ions, so we need to know the charges of common cations and anions, especially polyatomic ions.

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Common Polyatomic Ions (to remember):

| Ion | Formula | Charge |
|-----|--------|--------|
| Chromate | CrO₄²⁻ | -2 |
| Carbonate | CO₃²⁻ | -2 |
| Nitrate | NO₃⁻ | -1 |
| Sulfate | SO₄²⁻ | -2 |
| Phosphate | PO₄³⁻ | -3 |
| Chloride | Cl⁻ | -1 |
| Chlorate | ClO₃⁻ | -1 |
| Acetate | CH₃CO₂⁻ or C₂H₃O₂⁻ | -1 |
| Cyanide | CN⁻ | -1 |
| Hydrogen carbonate / Bicarbonate | HCO₃⁻ | -1 |
| Hydroxide | OH⁻ | -1 |

Cations:
- Sodium (Na⁺)
- Calcium (Ca²⁺)
- Magnesium (Mg²⁺)
- Aluminum (Al³⁺)
- Lithium (Li⁺)
- Ammonium (NH₄⁺)
- Cesium (Cs⁺)
- Potassium (K⁺)
- Barium (Ba²⁺)
- Rubidium (Rb⁺)
- Strontium (Sr²⁺)

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Now let’s complete the table:

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Part 1: Name → Formula

1. Sodium chromate
Na⁺ and CrO₄²⁻ → Need 2 Na⁺ for 1 CrO₄²⁻ → Na₂CrO₄

2. Calcium carbonate
Ca²⁺ and CO₃²⁻ → Charges balance directly → CaCO₃

3. Magnesium nitrate
Mg²⁺ and NO₃⁻ → Need 2 NO₃⁻ → Mg(NO₃)₂

4. Aluminum sulfate
Al³⁺ and SO₄²⁻ → LCM of 3 and 2 is 6 → 2 Al³⁺ (6+) and 3 SO₄²⁻ (6-) → Al₂(SO₄)₃

5. Lithium phosphate
Li⁺ and PO₄³⁻ → Need 3 Li⁺ → Li₃PO₄

6. Ammonium chloride
NH₄⁺ and Cl⁻ → NH₄Cl

7. Cesium chlorate
Cs⁺ and ClO₃⁻ → CsClO₃

8. Potassium sulfate
K⁺ and SO₄²⁻ → 2 K⁺ needed → K₂SO₄

9. Barium acetate
Ba²⁺ and CH₃CO₂⁻ → 2 acetate ions → Ba(CH₃CO₂)₂ or Ba(C₂H₃O₂)₂

10. Rubidium cyanide
Rb⁺ and CN⁻ → RbCN

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Part 2: Formula → Name

11. KCH₃CO₂
K⁺ and CH₃CO₂⁻ → Potassium acetate

12. Mg₃(PO₄)₂
Mg²⁺ and PO₄³⁻ → Magnesium phosphate

13. Al(ClO₃)₃
Al³⁺ and ClO₃⁻ → Aluminum chlorate

14. CaSO₄
Ca²⁺ and SO₄²⁻ → Calcium sulfate

15. Sr(HCO₃)₂
Sr²⁺ and HCO₃⁻ → Strontium hydrogen carbonate (or strontium bicarbonate)

16. NaNO₃
Na⁺ and NO₃⁻ → Sodium nitrate

17. Li₂CO₃
Li⁺ and CO₃²⁻ → Lithium carbonate

18. Ba(NO₃)₂
Ba²⁺ and NO₃⁻ → Barium nitrate

19. Cs₂CrO₄
Cs⁺ and CrO₄²⁻ → Cesium chromate

20. NH₄OH
NH₄⁺ and OH⁻ → Ammonium hydroxide

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✔ Final Completed Table:

| Name of Ionic Compound | Formula of Ionic Compound |
|-------------------------------|-------------------------------|
| 1. Sodium chromate | Na₂CrO₄ |
| 2. Calcium carbonate | CaCO₃ |
| 3. Magnesium nitrate | Mg(NO₃)₂ |
| 4. Aluminum sulfate | Al₂(SO₄)₃ |
| 5. Lithium phosphate | Li₃PO₄ |
| 6. Ammonium chloride | NH₄Cl |
| 7. Cesium chlorate | CsClO₃ |
| 8. Potassium sulfate | K₂SO₄ |
| 9. Barium acetate | Ba(CH₃CO₂)₂ |
| 10. Rubidium cyanide | RbCN |
| 11. Potassium acetate | KCH₃CO₂ |
| 12. Magnesium phosphate | Mg₃(PO₄)₂ |
| 13. Aluminum chlorate | Al(ClO₃)₃ |
| 14. Calcium sulfate | CaSO₄ |
| 15. Strontium hydrogen carbonate | Sr(HCO₃)₂ |
| 16. Sodium nitrate | NaNO₃ |
| 17. Lithium carbonate | Li₂CO₃ |
| 18. Barium nitrate | Ba(NO₃)₂ |
| 19. Cesium chromate | Cs₂CrO₄ |
| 20. Ammonium hydroxide | NH₄OH |

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🔍 Key Tips:

- Always check charge balance.
- Use parentheses around polyatomic ions when more than one is needed.
- Remember that ammonium (NH₄⁺) is a polyatomic cation.
- Hydroxide (OH⁻) and hydrogen carbonate (HCO₃⁻) are common polyatomic anions.

Let me know if you'd like a printable version or explanation for any specific compound!