Organic Chemistry Past Paper PDF

1) What is the suffix used to name alkanes according to IUPAC nomenclature? a) -ene b) -yne c) -ane d) -ol Answer: c) -ane 2) In naming an alkane, what is the first step to identify? a) Substituents b) Functional groups c) Longest chain d) Branches Answer: c) Longest chain 3) How are substituents na...

1) What is the suffix used to name alkanes according to IUPAC nomenclature? a) -ene b) -yne c) -ane d) -ol Answer: c) -ane 2) In naming an alkane, what is the first step to identify? a) Substituents b) Functional groups c) Longest chain d) Branches Answer: c) Longest chain 3) How are substituents named in alkane nomenclature? a) Using numbers b) Using the suffix -ene c) Using the letters "yl" d) Using Greek letters Answer: c) Using the letters "yl" 4) What is the general term for substituent groups in alkane nomenclature? a) Alkene groups b) Alkyl groups c) Hydroxyl groups d) Carbonyl groups Answer: b) Alkyl groups 5) Which reaction is used for the synthesis of alkanes by heating an alkyl halide with sodium metal? a) Hydrogenation b) Clemmensen reduction c) Wurtz reaction d) Halogenation Answer: c) Wurtz reaction 6) What is the general reactivity of alkanes towards chemical reagents? a) Highly reactive b) Moderately reactive c) Inert d) Unstable Answer: c) Inert 7) What type of reaction do alkanes undergo with halogens in the presence of heat or light? a) Hydrogenation b) Halogenation c) Oxidation d) Reduction Answer: b) Halogenation 8) How are alkyl halides classified based on the number of halogen atoms attached to the carbon? a) Primary, secondary, tertiary b) Mono, di, tri c) Alkylidene, alkylene d) Geminal, vicinal Answer: a) Primary, secondary, tertiary 9) Which method is used to synthesize alkyl halides from alkanes? a) Free radical halogenation b) Hydrogenation c) Wurtz reaction d) Clemmensen reduction Answer: a) Free radical halogenation 10) In nucleophilic substitution reactions, what happens to the leaving group? a) It stays attached to the substrate b) It forms a new bond with the nucleophile c) It comes away with an electron pair d) It becomes a nucleophile Answer: c) It comes away with an electron pair 11) What is the stereochemistry of nucleophilic substitution S1 reactions? a) Inversion, back side attack b) Retention and racemization c) Stereospecific d) Reactivity 3o > 2o > 1o Answer: b) Retention and racemization 12) Which type of solvent is preferred for nucleophilic substitution reactions? a) Polar protic solvent b) Aprotic polar solvent c) Non-polar solvent d) Hydrophobic solvent Answer: a) Polar protic solvent 13) How is the nomenclature of alkenes different from alkanes? a) Alkenes have a different suffix b) Alkenes have a different prefix c) Alkenes have a different numbering system d) Alkenes have a different functional group Answer: a) Alkenes have a different suffix 14) In naming alkenes, where should the π bond receive the lowest possible number? a) At the end of the chain b) In the middle of the chain c) Near the substituents d) Despite the presence of alkyl substituents Answer: d) Despite the presence of alkyl substituents