19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
Among the following alkyl halides, choose the one with the lowest boiling point.
Major (Excess) CH CH NH CH I P -> P should be
KSH -> P should be (a) (b)
Θ H C-SNa +CH CH -X -> The reaction is fastest when X is:
Haloforms are trihalogen derivatives of
This reaction follows
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: 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: Chlorination of allylic hydrogen is difficult than vinylic hydrogen. Reason: Allyl radical is stabilised by resonance.
Assertion: SN2 reaction of CH3––Br is faster in Cl CH S – SCH3 Cl (CH ) CHS 3 2 – SCH(CH ) 3 2 DMSO than in H2O. Reason: DMSO has greater capability to solvate nucleophile.
Assertion: Allyl halide (CH2=CH–CH2X) is more reactive than CH3CH2CH2X in a SN2 reaction. Reason: Allyl halide forms a resonance stabilized carbocation
Assertion: Consider the following SN2 reactions. (I) and (II) Reaction (II) occurs at a faster rate than (I) Reason: Anion of reaction (II) is a stronger base than the anion of reaction (I).
Assertion: Rate of reaction is dependent only on the concentration of nucleophile in SN1 reactions. Reason: Polar solvent favors SN1 reaction.
Assertion: Heavy metal ions Ag + or Pb 2+ decrease SN1 reactivity. Reason : They aid ionisation of RX.
Assertion: In SN1 mechanism, the product with inversion of configuration is obtained in a higher amount compared to the product with the retention of configuration. Reason: Front side attack of nucleophile is hindered…
Assertion: Benzyl bromide when kept in acetone – water, produces benzyl alcohol. Reason: The reaction follows SN2 mechanism.
Assertion: Consider the following synthesis CH3ONa + PhBr Path–II yields better yield of product than Path-I. Reason: CH3ONa is stronger base than PhONa.
Which of the following bases would give the best yield for the substitution product when reacted with 2-chloropropane?
Which of the following is the best synthesis of compound shown? (a) (b) (c) (d)
CH CH CH CH Br DMF CH CH O -> This reaction would follow which of the following pathway predominantly?
1-hexene is formed when methoxide reacts with
Debromination of meso dibromobutane will give the product as:
Find the major product of the following reaction: (a) (b) (c) (d)
Assertion (A): The boiling points of alkyl halides decreases in the order RI > RBr > RCl > RF Reason (R): The boiling points of alkyl chlorides, bromides and iodides are considerably higher than that of the hydrocarb…
A bromoalkane ‘X’ reacts with magnesium in dry ether to form compound ‘Y’. The reaction of ‘Y’ with methanol followed by hydrolysis yield an alcohol having molecular formula, C4H10O. The compound ‘X’ is (AIIMS 2018)