Carbon: Properties, States, and Significance

Carbon and Its Properties

• Carbon's symbol is C.
• Its atomic number is 6.
• Carbon has an atomic mass of 12.
• The electronic configuration of carbon is 2,4.
• Carbon has a valency of 4.
• It is classified as a nonmetallic element.
• Atomic number represents an element's position in the periodic table.
• Carbon's atomic number of 6 means it has 6 electrons.
• Electronic configuration splits how electrons are arranged around the atom.
• Carbon's first orbit must have 2 electrons, leaving 4 electrons for the second orbit.
• The second orbit needs 8, but carbon only has 4, indicating a valency of 4.

Origin and States of Carbon

• The name "carbon" originates from the Latin word "carbo", meaning coal.
• Carbon exists in two states: free state and combined (compound) state.
• Free state examples include diamond and graphite, made of single element only.
• Compound state examples include calcium carbonate, fossil fuels, and nutrients (proteins, fats, carbohydrates).
• Nutrients contain carbon in combined form.

Allotropy of Carbon

• Allotropy refers to elements having different forms with the same chemical properties but different physical properties.
• Different forms of carbon have identical chemical properties, but diverse physical appearances.

Types of Allotropes

• Allotropes of carbon are classified into two forms: crystalline and non-crystalline.
• Crystalline forms: diamond, graphite, and fullerene.
• Non-crystalline forms: coal, charcoal, and coke.

Types of Coal

• Coal further divided into: peat, lignite, bituminous coal, and anthracite.
• A tree diagram can help visually organize the allotropes and types of coal.

Crystalline Forms Explained

• Crystalline forms have a crystal structure with a regular and defined shape.
• Atoms are arranged in a definite manner.
• High melting and boiling points.
• Possess sharp edges and plane surfaces.

Diamond Structure

• Diamond: Each carbon atom is bonded to four neighboring carbon atoms via covalent bonds.
• Covalent bonds involve sharing electrons between atoms.
• Diamond is known for its hardness.

Diamond Properties and Uses

• Diamond properties include density and a high melting point.
• Diamonds don't dissolve in solvents.
• Diamond applications: ornaments, glass cutting, rock drilling machines, diamond polishing, and eye surgery.

Graphite Structure

• Graphite: Each carbon atom is bonded to three other carbon atoms, forming hexagonal layers.
• The layers give it a unique structure.

Graphite Properties and Uses

• Graphite is black, soft, brittle, and slippery.
• It is a good conductor of electricity.
• Graphite does not dissolve in most solvents.
• Layered structure enables its use in writing because layers slide and leave marks on paper.
• Graphite applications: pencil leads, paints, polishes, and carbon electrode production.

Fullerene and Discovery

• Fullerenes: A rare allotrope of carbon.
• Named after Buckminster Fuller by the researcher.
• C60 (Buckminsterfullerene) was the first example.

Properties and Composition

• C60, C70, C76, C82, and C86 are examples.
• Fullerene molecules resemble Buckyballs and Bucky tubes.
• Contain 30 to 900 carbon atoms per molecule.
• Fullerenes are soluble in organic solvents.

Uses of Fullerene

• Used as insulators.
• Utilized as catalysts in water purification.
• Exhibit superconductivity under certain conditions.

Non-Crystalline Forms Details

• Non-crystalline mentioned: coal, charcoal, and coke.

Coal Composition

• Coal: A fossil fuel.
• Contains carbon, hydrogen, and oxygen.
• Exists as a solid.

Stages of Coal

• Coal has four types: peat, lignite, bituminous, and anthracite, representing stages of formation.
• Peat is the first stage with a high water content and less than 60% carbon.
• Lignite contains 60-70% carbon.
• Bituminous coal contains 70-90% carbon.
• Anthracite contains 95% or more carbon.
• Anthracite is the purest form of coal.

Charcoal Details

• Charcoal made from animal bones or wood.
• Also made by burning the wood with restricted air.

Charcoal and Coal Uses

• Coal is a fuel in factories and homes.
• Making of coke, coal gas, and coal tar.
• Charcoal is used to purify water.
• Charcoal can purify organic materials.

Coke Details

• Coke: Pure carbon residue after coal gas is removed from coal.

Coke Uses

• Reducing agent.
• Domestic fuel use.

Introduction to Hydrocarbons

• Hydrocarbons are compounds containing hydrogen and carbon.

Types of Hydrocarbons

• Hydrocarbons: Open chain vs closed chain - open chains: saturated vs unsaturated.
• Saturated hydrocarbons have single bonds (alkanes).
• Unsaturated hydrocarbons have double (alkenes) or triple bonds (alkynes).
• The suffixes "-ane," "-ene," and "-yne" are important for naming hydrocarbons.

Carbon Dioxide Properties

• Includes molecular formula, mass, and melting point.

Chemical Properties

• Sodium hydroxide + carbon dioxide -> sodium carbonate + water.
• Aqueous sodium carbonate + carbon dioxide -> sodium bicarbonate (baking soda).

Uses of Carbon Dioxide

• Carbon Dioxide is used in aerated drinks.
• Solid carbon dioxide is used in cold storage.
• Fire extinguishers.
• Decaffeination of coffee.
• Used by plants for photosynthesis.

Fire Extinguisher Mechanism

• Main container holds sodium bicarbonate.
• Glass capsule holds concentrated form of sulphuric acid.
• Activating the nozzle breaks the glass and acid reacts with sodium bicarbonate.
• The reaction releases carbon dioxide gas to smother flames.
• Use for SMALL fires.
• Carbon dioxide is non-combustible (doesn't support combustion)
• Carbon dioxide is a non-conductor of electricity

Methane Description

• Methane: molecular formula is CH4, an example of hydrocarbon.
• Molecular weight of 16.

Methane Sources

• Methane is found in natural gas (87%), biogas and coal mines.
• Decomposition of organic matter absent any air

Methane Properties

• Melting point and boiling point.
• Colorless and gaseous at room temperature.

Methane Chemical Reaction

• Methane + oxygen -> carbon dioxide + water + heat.
• Methane undergoes chlorination when reacting with chlorine.

Methane Applications

• Fuel in industries, fabrics, paper mills and petroleum purification.
• Organic matter for ethanol and methyl chloride production.

Biogas Plants

• Animal waste, leaves, garbages decomposed where there is no air, producing biogas.
• Biogas is cheap.
• Used to generate electricity.
• Contains 55-60% methane, rest is carbon dioxide.
• Ethanoic acid decomposes to methane and carbon dioxide.