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Which of the following on heating with aqueous KOH, produces acetaldehyde:

A. CH3CH2Cl
B. CH2Cl.CH2Cl
C. CH3CHCl2 (Correct Answer)
D. CH3COCl
give reason n reaction pl

Answer :

bhalaraneha
Ans is c
The geminal dihalides are boiled with aqueous KOH or NaOH. It produces aldehydes and ketones. geminal dihalide (R-CHX2) having two halogen atoms situated on terminal carbon atom, are hydrolysed by aq. KOH or aq. NaOH first produced a unstable dihydroxy compound. Then converts into an aldehyde by loss of water molecule.
1-1- dichloroethane is germinal dihalide which react with KOH and produce unstable hydroxyl compound then loss of water molecule acetaldehyde produce

See the attachment for reaction. 
View image bhalaraneha
varshika1664

Answer:

The correct answer would be C. CH₃CHCl₂. When there is a reaction between CH₃CHCl₂ and aqueous KOH, the product formed is CH₃CHCl₂.

Explanation:

  • The reactant upon reacting with the aq. KOH follows the nucleophilic substitution reaction of the given halide group to give the corresponding Aldehyde substituted group as the main product.
  • Upon reaction, hydroxide ion which is produced, replaces the halogen atom in the alkyl halide which is reactant and thus, an Aldehyde is formed.

Mechanism:

  • CH₃CHCl₂ upon reaction with aq. KOH replaces two of it's chloride ions with the formed hydroxide ions.
  • Because of the bulky nature of formed hydroxide ions, the formation of the water molecules further takes place.

Hence, in this way, Acetaldehyde which is an Aldehyde is formed.

→ Reaction of 1, 1-dichloroethane with aq. KOH :

                CH₃CHCl₂ + 2KOH        →        CH₃CHO + 2KCl + H₂O

                                                              (Acetaldehyde)

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