Free NEET Chemistry multiple-choice questions on Reaction Intermediates. Attempt each question and reveal the answer with a full explanation.
Heterolytic fission of C-Cl bond produces: A carbocation and a chloride ion Two free radicals A carbanion and a chloronium ion A carbocation and a chlorine free radical Which of the following intermediates has a planar structure? Free radicals and Carbocations Carbanions only Carbocations only Free radicals only Which of the following carbocations is the most stable? (CH 3) 3C + (C 6H 5) 3C + CH 3-CH 2 + CH 2=CH-CH 2 + Which of the following intermediates is neutral? Carbene Carbocation Carbanion Nitronium ion Which of the following is the most stable carbanion? HC ≡ C - CH 2 = CH - CH 3 - CH 2 - (CH 3) 3C - The reaction intermediate formed in the Reimer-Tiemann reaction is: Dichlorocarbene ( :CCl 2 ) Free radical Carbanion Carbocation Which of the following is the most stable free radical? (C 6H 5) 2Ḋ H (CH 3) 3Ḋ CH 2=CH-Ḋ H 2 CH 3-Ḋ H 2 Which of the following intermediates has a triplet state and a singlet state? Carbene Carbocation Carbanion Free Radical The reaction of chloroform with alcoholic potassium hydroxide ( KOH ) generates which reactive intermediate? Dichlorocarbene ( :CCl 2 ) Trichloromethyl anion ( CCl 3 - ) Chlorine free radical ( Cl . ) Dichloromethyl carbocation ( CHCl 2 + ) Which of the following species is known as the 'Acylium' ion? R-C O + R-C +=O R-CH 2 + R-C=O - Which of the following intermediates is paramagnetic in nature? Free radical Carbocation Carbanion Singlet Carbene Which of the following intermediates is produced during the homolytic fission of a C-C bond? Free radical Carbocation Carbanion Carbene The most stable carbocation among the following is : The relative stability of the following carbanions is in the order: (I) CH C - , (II) CH 2=CH - , (III) CH 3-CH 2 - . I > II > III III > II > I II > I > III I > III > II Which of the following intermediates has the highest energy? Methyl radical Methyl carbocation Methyl carbanion They are all equal Which of the following carbocations will undergo rearrangement to a more stable structure? CH 3-CH(CH 3)-CH 2 + (CH 3) 3C + CH 3CH 2 + C 6H 5CH 2 + In the reaction of CH 3CH=CH 2 with HCl , the major product is 2-chloropropane. This is due to the formation of a more stable: Secondary carbocation Primary carbocation Secondary free radical Carbanion Identify the correct order of stability of the following carbanions: (I) (CH 3) 3C - , (II) (CH 3) 2CH - , (III) CH 3CH 2 - , (IV) CH 3 - . IV > III > II > I I > II > III > IV IV > I > II > III III > II > I > IV The reaction of HBr with CH 3-CH=CH 2 in the presence of peroxide follows which mechanism? Free radical addition Electrophilic addition Nucleophilic substitution Free radical substitution The hybridization of Carbon in the free radical CH 3 is: sp 2 sp 3 sp dsp 2 Which amongst the following is the most stable carbocation :- CH3 - + C H2 + C H3 CH3 - CH3 | CH3 | + C CH3 - CH3 | + C H The pair of electron in the given carbanion, CH3C C - , is present in which of the following orbitals ? 2p sp 3 sp 2 sp A tertiary butyl carbocation is more stable than a secondary butyl carbocation because of which of the following ? + R effect of – CH3 groups – R effect of – CH3 groups Hyperconjugation – I effect of – CH3 groups