Aldehydes, Ketones and Carboxylic Acids

Aldehydes, Ketones and Carboxylic Acids

Question

Write the structures of A, B, C, D and E in the following reactions:


Or

(a)Write the chemical equation for the reaction involved in Cannizzaro reaction.
(b)Draw the structure of the semicarbazone of ethanal.
(c)Why pKa of F-CH2-COOH is lower than that of Cl−CH2−COOH?
(d)Write the product in the following reaction:
CH subscript 3 minus CH equals CH minus CH subscript 2 CN space rightwards arrow from left parenthesis ii right parenthesis space straight H subscript 2 straight O to left parenthesis straight i right parenthesis space DIBAL minus straight H of

(e)How can you distinguish between propanal and propanone?

Answer

Or
c) Fluorine is more electronegative than chlorine. The presence of fluorine in a molecule will make it more acidic. Thus, the pKa of F−CH2−COOH is lower than that of Cl−CH2−COOH.
d) left parenthesis straight d space right parenthesis space CH subscript 3 minus CH equals CH minus CH subscript 2 CN space rightwards arrow from straight H subscript 2 straight O to DIBAL minus straight H of space CH subscript 3 minus CH equals CH minus CH subscript 2 CHO
e) 

Propanal

Propanone

It forms silver mirror on reaction with Tollen's reagent.

It is not oxidised by Tollen's reagent.

It does not react with iodoform.

It gives positive iodoform test.

On reacting with Schiff's reagent, it gives pink colour.

It does not react with Schiff's reagent.

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