19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
Assertion: Treatment of either enantiomer of 2-chlorobutane with ethanolic KOH results in trans-2- butene as major elimination product. Reason: Elimination with ethanolic KOH is a bimolecular reaction.
Assertion: Ph–CO–CH2CH2OCH3 has greater reactivity for E1CB than for E2 reaction. Reason: A poor leaving group and acidic —H favour E1CB mechanism.
Assertion: The reaction of bulky base such as potassium tertiary butoxide [(CH3)3CO–K+] with secondary alkyl halides gives predominantly E2 elimination product rather than SN2 substitution product. Reason: The transit…
Assertion: p-nitrochlorobenzene is more reactive than m-nitrochlorobenzene towards aromatic nucleophilic substitution reaction. Reason: Nitro group from para and meta positions has opposite effect in aromatic nucleoph…
Assertion: A dichlorobenzene is slightly more reactive than chlorobenzene towards an aromatic nucleophilic substitution reaction. Reason: Chlorine has electron withdrawing effect on aromatic ring.
Assertion: Chloral reacts with phenyl chloride to form DDT. Reason: It is an electrophilic substitution reaction
Which one of the following will give racemised product in C2H5OH? (a) (b) (c) (d)
This reaction would follow which of the following pathway predominantly?
The rate of SN1 reaction is fastest with: (a) (b) (c) CH Br CH NO2 Br (d)
The order of reactivities of the following alkyl halides for a SN2 reaction is
Major product of the following reaction is: (a) (b) (c) (d)
(a) (b) (c) (d)
This reaction would follow which of the following pathway predominantly?
C6H6Cl6 is six membered cyclic compound in which each carbon carry one chlorine atom, on treatment with alcoholic KOH yields
1-pentene will be formed as major product when methoxide reacts with
What is true about the following reaction? (a)Only substitution product is formed. (b)Only elimination product is formed. (c)Both substitution and elimination products are formed and substitution dominates. (d)Both su…
The major alkene obtained when this alkyl halide is subjected to E1 reaction will be (a) (b) (c)
The major product obtained when this substrate is subjected to E1 reaction will (a) (b) (c)
Which of the following species is an electrophile?
Which of the following species is an electrophile?
Which of the following species is a nucleophile?
Which of the following species is a nucleophile? (a) CH O
Which of the following species is a nucleophile?
Which of the following species is a nucleophile?
The decreasing order of nucleophilicity among the nucleophiles