Polyatomic Ions Study Notes
Polyatomic Ions
Overview of Polyatomic Ions
- Polyatomic ions are ions composed of two or more atoms which are covalently bonded.
- They carry a net charge, which can be positive or negative.
Positive Polyatomic Ions
- Ion: NH₄⁺
Name: Ammonium - Ion: H₃O⁺
Name: Hydronium
Negative Polyatomic Ions
- Ion: OH⁻
Name: Hydroxide - Ion: CN⁻
Name: Cyanide - Ion: NO₂⁻
Name: Nitrite - Ion: NO₃⁻
Name: Nitrate - Ion: ClO⁻
Name: Hypochlorite - Ion: ClO₂⁻
Name: Chlorite - Ion: ClO₃⁻
Name: Chlorate - Ion: ClO₄⁻
Name: Perchlorate - Ion: SO₃²⁻
Name: Sulfite - Ion: SO₄²⁻
Name: Sulfate - Ion: HSO₄⁻
Name: Hydrogen sulfate (or Bisulfate) - Ion: CO₃²⁻
Name: Carbonate - Ion: HCO₃⁻
Name: Hydrogen carbonate (or Bicarbonate) - Ion: PO₄³⁻
Name: Phosphate - Ion: HPO₄²⁻
Name: Hydrogen phosphate - Ion: H₂PO₄⁻
Name: Dihydrogen phosphate - Ion: C₂O₄²⁻
Name: Oxalate - Ion: SCN⁻
Name: Thiocyanate - Ion: OCN⁻
Name: Cyanate - Ion: MnO₄⁻
Name: Permanganate - Ion: Cr₂O₇²⁻
Name: Dichromate - Ion: CrO₄²⁻
Name: Chromate - Ion: S₂O₃²⁻
Name: Thiosulfate
Summary Table of Common Polyatomic Ions
| Ion | Name | Charge |
|---|
| NH₄⁺ | Ammonium | +1 |
| OH⁻ | Hydroxide | -1 |
| CN⁻ | Cyanide | -1 |
| NO₂⁻ | Nitrite | -1 |
| NO₃⁻ | Nitrate | -1 |
| ClO⁻ | Hypochlorite | -1 |
| ClO₂⁻ | Chlorite | -1 |
| ClO₃⁻ | Chlorate | -1 |
| ClO₄⁻ | Perchlorate | -1 |
| SO₃²⁻ | Sulfite | -2 |
| SO₄²⁻ | Sulfate | -2 |
| HSO₄⁻ | Hydrogen sulfate (Bisulfate) | -1 |
| CO₃²⁻ | Carbonate | -2 |
| HCO₃⁻ | Hydrogen carbonate (Bicarbonate) | -1 |
| PO₄³⁻ | Phosphate | -3 |
| HPO₄²⁻ | Hydrogen phosphate | -2 |
| H₂PO₄⁻ | Dihydrogen phosphate | -1 |
| C₂O₄²⁻ | Oxalate | -2 |
| SCN⁻ | Thiocyanate | -1 |
| OCN⁻ | Cyanate | -1 |
| MnO₄⁻ | Permanganate | -1 |
| Cr₂O₇²⁻ | Dichromate | -2 |
| CrO₄²⁻ | Chromate | -2 |
| S₂O₃²⁻ | Thiosulfate | -2 |
Conclusion
- Proper identification and memorization of these polyatomic ions are crucial for understanding and solving chemical equations, as well as predicting the behavior of various chemical compounds.