Carbon and its compounds notes PDF

PRASHANT KIRAD Carbon And Its Compound Allotropes: the various physical forms in which an element can exist. Carbon: Carbon is the 15th most abundant in the earth's crust. Atomic number : 6...

PRASHANT KIRAD Carbon And Its Compound Allotropes: the various physical forms in which an element can exist. Carbon: Carbon is the 15th most abundant in the earth's crust. Atomic number : 6. DIAMOND GRAPHITE FULLURENCE Valency : 4 Atomic mass :12u. no. of protons = no. of 3D network, each neutrons = 6 Layers of hexagons Hollow, cage-like shell -KL carbon bonds with held by weak forces with 60 carbons; No. of electrons- 2 4 elctronic arrangment four others; very soft and slippery soccer ball shape. hard. Covalent bond chemical bond that involves the sharing of electrons to form Four strong Three covalent bonds Strong covalent electron pairs between atoms. covalent bonds per per carbon, with bonds in hexagons Three types of covalent bonding carbon; highly delocalized electrons. and pentagons. stable. Single Covalent Bond Double Covalent Bond Triple Covalent Hard, transparent, Properties of Covalent Compounds: Bond high refractive Unique electronic Low melting/boiling points due to weaker intermolecular forces Soft, used in pencils properties; used in index; jewelry, compared to ionic compounds. and lubricants. nanotech, drugs. abrasives. - Physical state can be solid, liquid, or gas. - Poor conductors of electricity as they lack charged particles. HYDROCARBON - Generally soluble in organic solvents, insoluble in water (exception: sugar in water). Catenation: Carbon forms strong covalent bonds with itself, creating chains, branches, or rings. Aliphatic Aromatic hydrocarbons Polymerisation: Small molecules (monomers) join to form large molecules (polymers). Unsaturated Saturated Isomerism: Compounds with the same molecular formula but different structures. ALKANES ALKENE ALKYNES Tetravalency of Carbon: Carbon has four valence electrons, forming Single bond Double bond Triple bond four covalent bonds instead of gaining or losing electrons, ensuring stability and diverse organic compounds. ALKANES ALKENE Functional groups: In hydrocarbons, hydrogen atoms can be replaced by heteroatoms (e.g., Cl, S, N, O), forming functional groups that determine the compound’s reactivity and properties. Rules for Naming Compounds with Functional Groups Common Functional Groups & Their Formulae: 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. Three types of Hydrocarbons Number the chain to give the functional group the lowest possible Straight chain : Each carbon atom is number. bonded to either one or two other Functional groups have priority over alkanes, alkenes, and alkynes. carbon atom Use suffix or prefix based on the functional group. Branched chain: Each carbon atom is If multiple groups are present, the most important one gets the bonded to one, two, or more than two suffix. other carbon atoms ALKYNES Priority Order (Highest to Lowest): Cyclic Hydrocarbon: Carbon atoms form a closed ring -COOH > -CHO > -CO- > -OH > -NH₂ structure. e.g. Cyclohexane (C₆H₁₂), Benzene (C₆H₆). Homologous series: a collection of compounds with the same general formula that COMMON NOMENCLATURE: They are named after their sources of differ only in the carbon chain length. isolation. Formic acid derives from "Formectus," meaning red ant, and -Homologues share the same general formula. acetic acid from "Acetum," meaning vinegar. - Differ by a –CH₂ group; molecular mass difference is 14 µ. International Union of Pure and Applied Chemistry (IUPAC), - Similar chemical properties. founded in 1919, establishes standardized naming rules in - Gradual change in physical properties. chemistry - Functional group influences properties. Isomerism Compounds with identical molecular formula but different structures. NAME THESE Chemical properties of carbon Compounds Denatured alcohol is ethanol mixed with chemicals to make it unfit Combustion (Burning) for drinking. It is used in industries for cleaning, fuel, and as a Carbon compounds burn in oxygen (O₂) to form CO₂, H₂O, and solvent. The added substances, like methanol, make it poisonous heat.Example: CH₄ + 2O₂ → CO₂ + 2H₂O + Heat and undrinkable to avoid misuse. Denatured alcohol is cheaper than Oxidation pure ethanol due to tax exemptions. Alcohols are oxidized to acids using KMnO₄ or K₂Cr₂O₇. Example: CH₃CH₂OH + [O] → CH₃COOH Ethanoic Acid (CH₃COOH): Addition Reaction Commonly known as acetic acid, belongs to the carboxylic acid group. Unsaturated hydrocarbons (alkenes, alkynes) add H₂ in the presence 5-8% solution in water is called vinegar, used as a preservative in of Ni/Pd catalyst. pickles. Melting point: 290 K; freezes in winter, hence called glacial Example: CH₂=CH₂ + H₂ → CH₃-CH₃ acetic acid. Weak acid compared to mineral acids like HCl (does not Substitution Reaction fully ionize in water). Alkanes react with halogens (Cl₂, Br₂) in the presence of sunlight. Reactions of Ethanoic Acid: Example: CH₄ + Cl₂ → (Sunlight) → CH₃Cl + HCl 1. Esterification Reaction: Reacts with ethanol in the presence of Chemical properties of Ethanol and Ethanoic Acid concentrated H₂SO₄ to form ester (sweet-smelling, used in Ethanol (C₂H₅OH): perfumes & flavoring agents). Physical Properties of Ethanol: Ethanol is a liquid at room temperature. It is soluble in water in all proportions. Commonly known as alcohol, it is the active ingredient in alcoholic 2. Saponification reaction: Process of converting esters into salts drinks. of carboxylic acids and ethanol by treating them with a base. It is a 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. 3. Reaction with Bases: Reacts with sodium hydroxide to form Equation: 2Na + 2C₂H₅OH → 2C₂H₅O⁻Na⁺ + H₂ sodium ethanoate (sodium acetate) and water. Dehydration of Ethanol to Ethene: CH₃COOH + NaOH → CH₃COONa + H₂O Ethanol is heated with excess concentrated sulphuric acid at 443 4. Reaction with Carbonates and Hydrogencarbonates: Reacts K, leading to the removal of water (dehydration) and formation of with Na₂CO₃ or NaHCO₃, producing carbon dioxide, water, and ethene. sodium acetate. Equation: C₂H₅OH → CH₂=CH₂ + H₂O (In presence of hot 2CH₃COOH + Na₂CO₃ → 2CH₃COONa + H₂O + CO₂ conc. H₂SO₄) CH₃COOH + NaHCO₃ → CH₃COONa + H₂O + CO₂ Sulphuric acid acts as a dehydrating agent. Structure of Soap/Detergent Molecule Hard Water Soft Water Soap/Detergent molecules have two ends: Hydrophilic head (Water-attracting, polar) Hydrophobic tail (Oil-attracting, non-polar) Contains high mineral content, mainly Contains low mineral content, mainly calcium (Ca²⁺) and magnesium (Mg²⁺) Cleansing Process (Micelle Formation) sodium (Na⁺) or potassium (K⁺) ions. ions. Oil and dirt do not mix with water. When soap/detergent is added, the hydrophobic tail attaches to Does not lather easily with soap. Lathers easily with soap. grease/dirt, while the hydrophilic head remains in water. The molecules arrange themselves Forms scum and scale in pipes, in a micelle structure, surrounding boilers, and appliances. Does not form scum or scale. the dirt. The dirt gets trapped inside Can cause roughness in hair and skin. Feels smooth on skin and hair. micelles and is lifted off the surface. When rinsed with water, the Example: Groundwater, well water. Example: Rainwater, distilled water. micelles are washed away, removing dirt Soap Detergents Chapter ka KAZAANA: IUPAC Naming Molecules of soap are sodium or Detergents are sodium salts of sulphonic Electron Dot Structure (Ethanol, Amine) potassium salts of long-chain acids or ammonium salts with chloride or Homologous Series (MCQs) carboxylic acids. bromide ions. Important Reactions: Esterification, Saponification, Dehydration of Ethanol Not so effective in hard water. Effective even in hard water. Working of Soap (diagram) Relatively weak cleansing action. Strong cleansing action. Soaps are biodegradable. Most of them are non-biodegradable.