Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main20199 Apr 2019Evening ShiftChemistryAldehydes and KetonesActual

In the following reaction carbonyl compound + M e O H ⇌ H C l a c e t a l Rate of the reaction is the highest for:

Options

  1. AAcetone as substrate and methanol in stoichiometric amount
  2. BPropanal as substrate and methanol in excess
  3. CPropanal as substrate and methanol in stoichiometric amount
  4. DAcetone as substrate and methanol in excess

Correct answer

B. Propanal as substrate and methanol in excess

Step-by-step solution

Acetal is form from the reaction of aldehyde with excess of M e O H Formation of an acetal occurs when the hydroxyl group of a hemiacetal becomes protonated and is lost as water. The carbocation that is produced is then rapidly attacked by a molecule of alcohol. Loss of the proton from the attached alcohol gives the acetal.

Practice Aldehydes and Ketones on Quantrex Academy →

More from Aldehydes and Ketones

Consider the following reaction. The major product (P) formed is: 2026' x ' is the product which is obtained from benzene by reacting it with carbon monoxide and hydrogen chloride in the presence of cuprous chloride. ' y ' is the major product obtain 2026' x ' is the product which is obtained by the hydrolysis of prop-1-yne in the presence of mercuric sulphate under dilute acidic medium at 333 K. ' y ' is the product which is obtai 2026Given below are two statements: Statement-I: The condensation reaction between CH₃-CH=O and under optimum pH will produce . Statement-II: The molecule will generate Ph-CH=O in the 2026An organic compound " x " where molar ratio of C, O and H are equal, on treatment with 50 % KOH under reflux followed by acidification produced " y ". The most likely structure of 2026Given below are the four isomeric compounds ( P , Q , R , S ) Identify correct statements from below. A. Q , R and S will give precipitate with 2,4- DNP . B. P and Q will give posi 2026Given below are two statements: Statement I : Cross aldol condensation between two different aldehydes will always produce four different products. Statement II : When semicarbazid 2026Which of the following statements are TRUE about Haloform reaction?: A. Sodium hypochlorite reacts with KI to give KOI. B. KOI is a reducing agent. C. , -unsaturated methylketone ( 2026 Full Aldehydes and Ketones list All JEE Main PYQs