Carbon Compounds — Maharashtra (SSC) Class 10 Science Solutions (Free)

In covalent bonding, atoms share electron pairs. Carbon has 4 valence electrons and forms 4 covalent bonds. This allows carbon to bond with itself and other nonmetals (H, O, N, S) to form millions of compounds. C-C bonds allow chain formation; C=C and C≡C bonds create different structures and reactivities. This is why carbon chemistry is so diverse.

Hydrocarbons are organic compounds containing only carbon and hydrogen. Alkanes (CnH2n+2): single C-C bonds, saturated, examples CH4 (methane), C2H6 (ethane), C3H8 (propane). Alkenes (CnH2n): C=C double bonds, unsaturated, examples C2H4 (ethene), C3H6 (propene). Alkynes (CnH2n-2): C≡C triple bonds, examples C2H2 (acetylene).

Functional groups are specific atom groups that determine the chemical properties of organic compounds. Hydroxyl (-OH): found in alcohols, makes them polar and soluble. Carboxyl (-COOH): found in carboxylic acids, acidic due to H+ release. Amino (-NH2): found in amines and proteins, basic character. Each group imparts distinct reactivity and properties.

Polymers are large molecules made of repeating monomer units. Addition polymerization: monomers add directly without loss of atoms. Example: n(C2H4) → (-CH2-CH2-)n (polyethene). Condensation polymerization: monomers join with loss of small molecules like H2O. Example: formation of nylon (condensation of diamines and dicarboxylic acids). Uses: plastics, fibers, elastomers.

Isomerism is when compounds have the same molecular formula but different structural arrangements. Structural isomers have different arrangements of atoms. Example: C4H10 exists as n-butane (straight chain) and isobutane or 2-methylpropane (branched). These isomers have different boiling points and chemical properties despite the same molecular formula.