Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
COMEDK2024Evening ShiftChemistryAlcohols Phenols and EthersActual

Compounds A and B , having the same molecular formula ( C ₄ H ₈ O ) , react separately with CH ₃ MgBr , followed by reaction with dil. HCl to form compounds X and Y respectively. Compound Y undergoes acidic dehydration in presence of Conc. H ₂ SO ₄ much more readily than X . Compound Y also reacts with Lucas reagent, much more readily than X , with appearance of turbidity. Identify X and Y .

Options

  1. AX = Pentan -1- ol Y = Pentan -2- ol
  2. BX = Pentan-2-ol Y =2 -Methylbutan-2-ol
  3. CX = Butan-2-ol Y = 2-Methylpropan-2-ol
  4. DX = Pentan-1-ol Y =2- Methylpentan-2-ol

Correct answer

B. X = Pentan-2-ol Y =2 -Methylbutan-2-ol

Step-by-step solution

A and B have molecular formula C₄H₈O (carbonyl compounds). Reacting with CH₃MgBr adds one carbon, giving 5-carbon alcohols X and Y. Y undergoes dehydration and Lucas test much more readily than X Y is a tertiary alcohol, X is a secondary alcohol. Ketone: Butanone ( CH₃COCH₂CH₃ ) + CH₃MgBr H₃O^+ 2-Methylbutan-2-ol (3° alcohol) Y Aldehyde: Butanal ( CH₃CH₂CH₂CHO ) + CH₃MgBr H₃O^+ Pentan-2-ol (2° alcohol) X X = Pentan-2-ol, Y = 2-Methylbutan-2-ol

Practice Alcohols Phenols and Ethers on Quantrex Academy →

More from Alcohols Phenols and Ethers

Consider the series of reactions given and identify the final product [Z]. 2026An unsaturated organic compound (C₃ H₆ ), undergoes the following series of reactions: C ₃ H ₆ dil H₂SO₄ [ B ] ( Major Product ) + HCl / ZnCl₂ [ C ] Na_ (s) / dry ether [ D ] Ident 2026Two statements [A] and [B] are given below. Choose the correct option. A) Protonated R - CH₂- OH can serve as Electrophiles while neutral R - OH acts as a Nucleophile. B) The bond 2026Choose the incorrect statement. 2026A compound [X] undergoes reactions as given. Identify compounds [C] and [D] formed in these reactions. 2026Choose the correct reason: o-hydroxybenzaldehyde is a liquid at room temperature while p -hydroxy-benzaldehyde is a high melting solid, because 2026Match reactions in Column I with the corresponding products formed as given in Column II. Column I Column II A. C ₆ H ₅ N ₂^+ Cl ^- + H ₂ O warm P. p–Bromophenol B. C ₆ H ₅ OH + Br 2026An aliphatic compound [X], Molecular formula ( C ₄ H ₁₀ O ) can be prepared from Acetone and R– Mg–X. [X] with 20% Phosphoric acid gives an unsaturated compound C ₄ H ₈ [Y]. Compou 2026 Full Alcohols Phenols and Ethers list All COMEDK PYQs