CBSE Class 12 Chemistry 2020 Delhi Set 1 Solved Paper

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Question : 36
Total: 37
(a) Write the products formed when benzaldehyde reacts with the following reagents :
(i) CH3CHO in presence of dilute NaOH

(iii)Conc. NaOH
(b) Distinguish between following:
(i) CH3CH=CHCOCH3 and CH3CH2 COCH=CH2
(ii) Benzaldehyde andBenzoic acid
OR
(a) Write the final products in the following:
(iii) CH2=CHCH2CN
(a) DIBALH
(b) H3O+

(b) Arrange the following in the increasing order of their reactivitytowards nucleophilic addition reaction:
(c) Draw the structure of 2, 4 DNP derivative of acetaldehyde.
Solution:  
(a)
(b) (i) CH3CH=CHCOCH3 gives iodoform test while CH3CH2COCH=CH2 does not give.
CH3CH=CH
C
O
CH3
+3NaOI
CH3I
Yellowppt.
+2NaOH
+CH3CH=CHCOONa
CH3CHCOCH=CH2+3NaOI No ppt
(ii) ● Benzaldehyde reacts with tollen's reagent to form silver mirror. Benzoic acid does not give this reaction.

● With NaHCO3 benzaldehyde does not react while benzoic acid produces brisk effervescences.
OR
(a)

(iii) CH2=CHCH2CN
(a) DIBALH
(b) H3O+
CH2=CHCH2
O
C
H

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