What is organic chemistry? — The study of carbon-containing compounds. Carbon is unique — it forms 4 bonds and chains of virtually unlimited length with itself and other elements, enabling millions of compounds.

What is a functional group? — An atom or group of atoms in an organic molecule that determines its characteristic chemical reactions and properties. The rest of the molecule is usually an inert carbon chain (R group).

What are hydrocarbons? — Organic compounds containing only carbon and hydrogen. Classified as alkanes (single bonds), alkenes (double bonds), alkynes (triple bonds), and aromatic (benzene ring).

What are alkanes and what is their general formula? — Hydrocarbons with only single C–C bonds — fully saturated. General formula: CₙH₂ₙ₊₂. Examples: methane (CH₄), ethane (C₂H₆), propane (C₃H₈).

What are the first 10 alkane names? — Methane (C1), Ethane (C2), Propane (C3), Butane (C4), Pentane (C5), Hexane (C6), Heptane (C7), Octane (C8), Nonane (C9), Decane (C10).

What are alkenes and what is their general formula? — Hydrocarbons with at least one C=C double bond — unsaturated. General formula: CₙH₂ₙ. Examples: ethene (C₂H₄), propene (C₃H₆). More reactive than alkanes.

What are alkynes and what is their general formula? — Hydrocarbons with at least one C≡C triple bond. General formula: CₙH₂ₙ₋₂. Examples: ethyne/acetylene (C₂H₂). Very reactive and used in welding torches.

What is benzene and why is it special? — Benzene (C₆H₆) is an aromatic hydrocarbon with a ring of 6 carbons and delocalized π electrons. It is unusually stable due to resonance. Basis of all aromatic compounds.

What is an alcohol functional group? — Contains an –OH (hydroxyl) group bonded to a carbon chain. General formula: R–OH. Examples: methanol (CH₃OH), ethanol (C₂H₅OH). Properties: polar, hydrogen bonding, high boiling point.

What are primary, secondary, and tertiary alcohols? — Classified by how many carbon atoms are bonded to the carbon bearing the –OH group. Primary (1°): 1 carbon. Secondary (2°): 2 carbons. Tertiary (3°): 3 carbons.

What is an aldehyde functional group? — Contains a –CHO group (carbonyl C=O at end of chain). General formula: R–CHO. Examples: formaldehyde (HCHO), ethanal (CH₃CHO). Have a distinctive sharp smell.

What is a ketone functional group? — Contains a C=O group bonded to two carbon atoms (carbonyl in the middle of chain). General formula: R–CO–R'. Example: propanone/acetone (CH₃COCH₃). Used as a solvent.

What is a carboxylic acid functional group? — Contains a –COOH group. General formula: R–COOH. Examples: methanoic acid (HCOOH), ethanoic acid (CH₃COOH/acetic acid). Weak acids with sharp, sour smells.

What is an ester functional group and how is it formed? — Contains a –COO– group. Formed by reaction of carboxylic acid + alcohol (esterification). Example: ethyl ethanoate (CH₃COOC₂H₅). Responsible for fruity smells and flavors.

What is an ether functional group? — Contains an –O– group between two carbon chains. General formula: R–O–R'. Example: diethyl ether (C₂H₅OC₂H₅). Used as a solvent and historically as an anesthetic.

What is an amine functional group? — Contains a –NH₂ group (or substituted versions –NHR or –NR₂). Amines are basic and have strong, fishy smells. Example: methylamine (CH₃NH₂). Building blocks of amino acids.

What is an amide functional group? — Contains a –CONH₂ group (carbonyl + amine). Formed from carboxylic acid + amine. Example: ethanamide (CH₃CONH₂). The peptide bond in proteins is an amide bond.

What is isomerism in organic chemistry? — When two or more compounds have the same molecular formula but different structural arrangements. Structural isomers differ in connectivity. Stereoisomers differ in spatial arrangement.

What are cis and trans isomers? — A type of geometric stereoisomerism in alkenes. Cis: Same groups on same side of double bond. Trans: Same groups on opposite sides. Different physical properties (boiling points, polarity).

What is addition reaction? — A reaction where atoms are added across a double or triple bond, converting it to a single bond. Example: ethene + H₂ → ethane (hydrogenation). Typical of alkenes.

What is substitution reaction in organic chemistry? — A reaction where one atom or group is replaced by another. Typical of alkanes (e.g., halogenation: CH₄ + Cl₂ → CH₃Cl + HCl in UV light).

What is elimination reaction? — A reaction where atoms are removed from adjacent carbons, forming a double bond. Opposite of addition. Example: dehydration of alcohol → alkene + water.

What is polymerization? — The process of joining many small monomer molecules into a large polymer chain. Addition polymerization: monomers with double bonds join without losing atoms (e.g., polyethylene from ethene).

What is IUPAC nomenclature? — The systematic naming system for organic compounds. Rules: 1. Find the longest carbon chain. 2. Number from the end closest to a substituent. 3. Name substituents as prefixes. 4. Use suffixes for functional groups (-ol, -al, -one, -oic acid).

What are the major organic reaction types to know? — 1. Addition (alkenes) 2. Substitution (alkanes, benzene) 3. Elimination (alcohols → alkenes) 4. Oxidation (primary alcohol → aldehyde → carboxylic acid) 5. Esterification (acid + alcohol → ester + water) 6. Hydrolysis (breaking bonds with water)