Chemistry

Theme: Carbon and Its Compounds

Introduction to Carbon

• Importance of Carbon: Carbon is a vital non-metallic element in Earth's crust.

  • Symbol: C

  • Atomic Number: 6

  • Mass Number: 12

• Presence of Carbon: Found in daily items such as food, clothing, and pencil lead.

Carbon Compounds and Organic Chemistry

• Approximately 85% of all known compounds contain carbon; Organic Chemistry focuses on carbon compounds.

  • Examples: vinegar, wool, starch, etc.

• Hydrocarbons: Compounds consisting only of carbon and hydrogen, crucial for fuels and energy.

• Carbon is essential for life, present in both free (diamond, graphite) and combined states (coal, petroleum).

• The word carbon is derived from the Latin word" carbo," meaning charcoal, which reflects its historical association with burning organic materials.

Allotropy and Allotropes of Carbon

• Allotropy: The property of an element to exist in multiple forms with identical chemical properties but different physical properties.

  • Examples: Diamond and graphite

• allotropes: different physical forms of an element. they have different physical forms but the same chemical properties.

• Reasons for Allotropy:

  • Different preparation methods

  • Energy variations involved

  • Diverse atomic arrangement

Types of Coal

1. Peat

   • Youngest form; 50-60% carbon; partially decayed plant matter.

   • Burns slowly, leaving ash.

2. Lignite

   • Soft, brown coal with 60-70% carbon.

   • Harder than peat, burns with lesser soot.

3. Bituminous

   • Most abundant type; 75-80% carbon. Used for heating.

4. Anthracite

   • Hardest coal with 90-95% carbon, high heat generation, burns slowly with minimal smoke.

• Uses of Coal:

  • Fuel for electricity and cooking, reducing agent in metal extraction, organic compound source.

Coke

• The black porous solid residue left after the destructive distillation of coal. Contains 95 to 98% of free carbon and is free from volatile impurities. Bad conductor of heat and electricity.

• Destructive distillation: coal is heated in the absence of air. It results in the formation of coke, coal gas, etc.

Kajal Preparation Activity

• Aim: To make kajal

• Materials: Mustard oil, lamp, cotton wick, metal plate

• Observation: Lampblack deposited on the plate from the flame.

Carbon and Its Occurrence

• Coal: Natural form of amorphous carbon found deep within the Earth.

  • Formation: From decomposed plants over millions of years under pressure.

• Carbonisation: Process converting organic matter into coal under heat and pressure.

Types of Charcoal

1. Wood Charcoal: Produced via wood distillation; black, porous.

2. Sugar Charcoal: Formed from sugar using acid.

3. Animal Charcoal: Derived from bones, used for purification.

4. Lampblack: Byproduct of burning hydrocarbons, used in various applications. Contains 98 to 99% of carbon

Fullerene

• A crystalline form with 20-900 carbon atoms; the common type known as C60 resembles a soccer ball.

• Preparation: From vaporised graphite in helium.

• Properties: Soluble in many solvents, stable, can become superconductive in some instances.

Graphite

• Conductivity: Good conductor of electricity due to free valence electrons.

• Structure: Hexagonal layers; soft and slippery due to weak interlayer binding.

• Uses: In pencils, lubricants, batteries, and nuclear reactors.

Diamond

• Properties: Transparent and colorless, hardest natural substance (3.5 g/cm³), good light refractor (high refractive index).

• Formed under extreme conditions; both natural and synthetic diamonds exist.

• Uses: In cutting tools, jewelry, and specific scientific applications.

Differences between Graphite and Diamond

Conclusion

• Carbon: Vital element with diverse allotropes and numerous applications in daily life and industry.

• Understanding its properties and behavior is crucial for chemistry and various fields of study.