Organic Chemistry

• Carbon accounts for being the 15th most abundant element in the Earth's crust.
• It has an atomic number of 6.
• Atomic mass is 12u.
• The number of protons and neutrons are both 6.
• The valence is 4

Shell Configuration

• K shell has 2 electrons.
• L shell has 4 electrons.
• Electronic arrangement is 2, 4.
• The symbol is C

Covalent Bonding

• Involves the sharing of electrons.
• Forms electron pairs between atoms.

Types of Covalent Bonds

• Single Covalent Bond
• Double Covalent Bond
• Triple Covalent Bond

Properties of Covalent Compounds

• Have low melting and boiling points.
• Due to weaker intermolecular forces.
• Are generally solid, liquid, or gas.
• Are poor conductors of electricity, lacking charged particles.
• Usually soluble in organic solvents.
• Insoluble in water, with the exception of sugar.

Catenation and Polymerization

• Catenation is carbon's ability to form strong covalent bonds with itself.
• Results in chains, branches, or rings.
• Polymerization involves small molecules (monomers) joining.
• Results in large molecules (polymers).

Isomerism and Tetravalency

• Isomerism: Compounds share the same molecular formula but have different structures.
• Tetravalency: Carbon possesses four valence electrons.
• Forms four covalent binds.
• Ensures stability and diverse organic compounds.

Allotropes

• Allotropes are various physical forms in which an element can exist.

Diamond

• 3D network structure.
• Each carbon bonds with four others.
• Very hard due to strong covalent bonds.
• Is transparent with a high refractive index.
• Used in jewelry and abrasives.

Graphite

• Consists of layers of hexagons held by weak forces.
• Soft and slippery with three covalent bonds per carbon.
• Has delocalized electrons.
• Is soft.
• Used in pencils and lubricants.

Fullurene

• Hollow, cage-like shape with 60 carbons, resembling a soccer ball.
• Strong covalent bonds.
• Has unique electronic properties.
• Used in nanotech and drugs.

Hydrocarbons

• Contain only carbon and hydrogen atoms.
• These can be saturated, unsaturated, or aromatic.
• Aliphatic: Straight or branched chain hydrocarbons.
• Aromatic hydrocarbons: Contain benzene rings.

Alkanes (Saturated)

• Single bonds.
• General formula: CnH2n+2.

Alkenes (Unsaturated)

• Contain double bonds.
• General formula: CnH2n.

Alkynes (Unsaturated)

• Triple bonds.
• General formula: CnH2n-2.

Functional Groups

• Hydrogen atoms in hydrocarbons can be replaced by heteroatoms.
• These atoms include Cl, S, N, and O.
• This forms functional groups that determine the compound's reactivity and properties.

Common Functional Groups and Formula

• Alcohol (-OH): Ends in -ol (e.g., Ethanol).
• Aldehyde (-CHO): Ends in -al (e.g., Ethanal).
• Ketone (-CO-): Ends in -one (e.g., Propanone).
• Carboxylic Acid (-COOH): Ends in -oic acid (e.g., Ethanoic acid).
• Amine (-NH2): Ends in -amine or starts with Amino-.

Naming Rules

• Identify the longest carbon chain.
• Number the chain to give the functional group the lowest possible number.
• Functional groups have priority over alkanes, alkenes, and alkynes.
• Use suffix or prefix based on the functional group.
• If multiple groups are present, the most important one gets the suffix.
• Priority Order (Highest to Lowest).
• COOH > -CHO > -CO- > -OH > -NH2

Homologous Series

• Collection of compounds with the same general formula.
• Differ only in the carbon chain length.
• Homologues share the same general formula.
• Differ by a -CH2 group.
• Mass difference is 14 μ.
• Have similar chemical properties.
• Show gradual changes in physical properties.
• Functional groups influence properties.

Isomerism

• Compounds.
• Have identical molecular formula but different structures.

Chemical Properties of Carbon Compounds

• Combustion (Burning): Carbon compounds burn in oxygen (O2) to form CO2, H2O, and heat.
• Oxidation: Alcohols are oxidized to acids using KMnO4 or K2Cr2O7.
• Addition Reaction: Unsaturated hydrocarbons (alkenes, alkynes) add H2 in the presence of Ni/Pd catalyst.
• Substitution Reaction: Alkanes react with halogens (Cl2, Br2) in the presence of sunlight.

Ethanol (C2H5OH) Properties

• Liquid at room temperature.
• Soluble in water in all proportions.
• Commonly known as alcohol, active ingredient in alcoholic drinks.
• Good solvent, used in medicines like tincture iodine, cough syrups, and tonics.

Reactions of Ethanol

• Reaction with Sodium: Ethanol reacts with sodium, producing hydrogen gas and sodium ethoxide. Equation: 2Na + 2C2H5OH → 2C2H5ONa + H2
• Dehydration to Ethene: Ethanol is heated with excess concentrated sulphuric acid at 443 K, leading to the removal of water (dehydration) and formation of ethene. Equation: C2H5OH → CH2=CH2 + H2O (In presence of hot conc. H2SO4) Sulphuric acid acts as a dehydrating agent.

Denatured and Ethanoic Acid

• Denatured alcohol is ethanol mixed with chemicals to make it unfit for drinking, cheaper due to tax exemptions.
• Ethanoic Acid (CH3COOH): Commonly known as acetic acid, belongs to the carboxylic acid group. A 5-8% solution in water is called vinegar, used as a preservative in pickles.

Reactions of Ethanoic Acid

• Esterification Reaction: Reacts with ethanol in the presence of concentrated H2SO4 to form ester (sweet-smelling, used in perfumes & flavoring agents).
• Saponification reaction: Process of converting esters into salts of carboxylic acids and ethanol by treating them with a base.
• Reaction with Bases: Reacts with sodium hydroxide to form sodium ethanoate (sodium acetate) and water.
• Reaction with Carbonates and Hydrogencarbonates: Reacts with Na2CO3 or NaHCO3, producing carbon dioxide, water, and sodium acetate.

Soap and Detergent Molecules

• Have two ends.
• A hydrophilic head.
• Water-attracting, polar.
• A hydrophobic tail.
• Oil-attracting, non-polar.

Cleansing Process (Micelle Formation)

• Oil and dirt do not mix with water.
• When soap/detergent is added, the hydrophobic tail attaches to grease/dirt.
• Hydrophilic head remains in water.
• The molecules arrange themselves in a micelle structure, surrounding the dirt.
• The dirt gets trapped inside micelles and is lifted off the surface.
• When rinsed with water, the micelles are washed away, removing dirt.

Types of molecules

• Soap molecules are sodium or potassium salts of long-chain carboxylic acids.
• Detergents are sodium salts of sulphonic acids or ammonium salts with chloride or bromide ions.
• Soaps are not so effective in hard water. Detergents are effective even in hard water
• Soaps have relatively weak cleansing action, while detergents have strong cleansing action
• Soaps are biodegradable, while detergents are mostly non-biodegradable

Water Types

• Hard Water: Contains high mineral content, mainly calcium (Ca2+) and magnesium (Mg2+) ions. Does not lather easily with soap.
• Soft Water: Contains low mineral content, mainly sodium (Na+) or potassium (K+) ions. Lathers easily with soap.