Key Points
Key Points: Sulphur - Allotropic Forms
Allotropes of Sulphur:
| Property | Rhombic (α) | Monoclinic (β) |
|---|---|---|
| Colour | Pale yellow | Bright yellow |
| Shape | Orthorhombic | Needle-shaped |
| Melting point | 385.8 K | 393 K |
| Density | 2.06 g/cm³ | 1.98 g/cm³ |
| Stability | Stable below 369 K | Stable above 369 K |
| Solubility | Insoluble in water, soluble in CS₂ | Soluble in CS₂ |
Allotropes of Group 16:
| Element | Allotropes |
|---|---|
| Oxygen | O₂, O₃ (ozone) |
| Sulfur | Rhombic, Monoclinic |
| Selenium | Red (non-metallic), Grey (metallic) |
| Tellurium | Crystalline, Amorphous |
| Polonium | α and β (both metallic) |
Key Points: Compounds of Sulphur
| Property | SO₂ (Sulphur dioxide) | H₂SO₄ (Sulphuric acid) |
|---|---|---|
| Preparation | FeS₂ + O₂ → SO₂ | Contact process |
| Physical | Colourless, pungent, poisonous gas | Colourless, dense, oily liquid |
| Nature | Reducing agent | Strong acid |
| Key reactions | With O₂ → SO₃ (V₂O₅) | Dehydrating agent |
| Special reaction | Decolourises KMnO₄ | Sugar → carbon |
| Other reactions | With NaOH → Na₂SO₃ | With salts → HCl |
| Uses | Bleaching, disinfectant | Fertilisers, industry |
Key Points: Oxoacids of Sulphur
| Name | Formula |
|---|---|
| Sulfurous acid | H₂SO₃ |
| Sulfuric acid | H₂SO₄ |
| Disulfuric (Pyrosulfuric) acid | H₂S₂O₇ |
| Peroxomonosulfuric acid | H₂SO₅ |
| Peroxodisulfuric acid | H₂S₂O₈ |
| Thiosulfuric acid | H₂S₂O₃ |
Key Points: Interhalogen Compounds
Types of Interhalogen Compounds:
| Type | Examples |
|---|---|
| XX′ | ClF, BrF, ICl, IBr |
| XX′₃ | ClF₃, BrF₃, IF₃ |
| XX′₅ | ClF₅, BrF₅, IF₅ |
| XX′₇ | IF₇ |
Methods of Preparation:
| Method | Reactions |
|---|---|
| Direct combination | Cl₂ + F₂ → 2ClF Br₂ + 3F₂ → 2BrF₃ I₂ + 3Cl₂ → 2ICl₃ |
| Halogen + interhalogen | Br₂ + BrF₃ → 3BrF Br₂ + ClF₃ → 2BrF₃ + BrCl |
| Special (ICl) | I₂ + KClO₃ → ICl + KIO₃ |
Key Points: Oxoacids of Halogens
| Oxidation state of X | Generic name | Oxoacids of fluorine | Oxoacids of chlorine | Oxoacids of bromine | Oxoacids of iodine |
|---|---|---|---|---|---|
| +1 | Hypohalous acid (HXO) | HOF | HOCl | HOBr | HOI |
| +3 | Halous acid (HXO₂) | – | HOClO | – | – |
| +5 | Halic acid (HXO₃) | – | HOClO₂ | HOBrO₂ | HOIO₂ |
| +7 | Perhalic acid (HXO₄) | – | HOClO₃ | HOBrO₃ | HOIO₃ |
Concepts [31]
- Group 15 Elements - The Nitrogen Family
- Group 15 Elements - The Nitrogen Family
- Dinitrogen
- Ammonia
- Oxides of Nitrogen
- Nitric Acid
- Phosphorus - Allotropic Forms
- Compounds of Phosphorus
- Phosphine
- Phosphorus Halides
- Oxoacids of Phosphorus
- Group 16 Elements - The Oxygen Family
- Group 16 Elements - The Oxygen Family
- Dioxygen
- Classification of Oxides
- Simple Oxides
- Ozone
- Sulphur - Allotropic Forms
- Compounds of Sulphur
- Sulphur Dioxide
- Oxoacids of Sulphur
- Sulphuric Acid
- Group 17 Elements - The Halogen Family
- Group 17 Elements - The Halogen Family
- Chlorine
- Hydrogen Chloride
- Interhalogen Compounds
- Oxoacids of Halogens
- Compounds of Halogens
- Group 18 Elements - The Noble gas Family
- Group 18 Elements - The Noble gas Family
