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CBSE Class 12 Chemistry 2017 Outside Delhi Set 1 Solved Paper

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Question : 26 of 26
Marks: +1, -0
(a) Write the product (s) in the following reactions:
(iii) CH3−CH=CH−CN→(b)H2O(a)DIBAL−H\mathrm{CH}_3-\mathrm{CH}=\mathrm{CH}-\mathrm{CN}\xrightarrow[(b)\mathrm{H}_2\mathrm{O}]{(a)\mathrm{DIBAL-H}}
(b) Give simple chemical tests to distinguish between the following pairs of compounds :
(i) Butanal and Butan-2-one
(ii) Benzoic acid and Phenol
OR
(a) Write the reactions involved in the following :
(i) Etard reaction
(ii) Stephen reduction
(b) How will you convert the following in not more than two steps :
(i) Benzoic acid to benzaldehyde
(ii) Acetophenone to benzoic acid
(iii) Ethanoic acid to 2-hydroxyethanoic acid
Solution:  
(iii) CH3−CH=CH−CHO\mathrm{CH}_3-\mathrm{CH}=\mathrm{CH}-\mathrm{CHO}
(b) (i) Tollen's reagent test : Add ammoniacal solution of silver nitrate (Tollen's reagent) in both the solutions. Butanal gives silver mirror whereas Butan-2-one does not.
(ii) Add neutral FeCl3\mathrm{FeCl}_3 in both the solutions, phenol forms violet colour but benzoic acid does not.
OR(a) (i) Etard reaction
(ii) Stephen reaction
  RCN+SnCl2+HCl→RCH\;\mathrm{RCN}+\mathrm{SnCl}_2+\mathrm{HCl}\rightarrow\mathrm{RCH} =NHRCHOH3O+=\mathrm{NH}\overset{\mathrm{H}_3\mathrm{O}^+}{\mathrm{RCHO}}
OR
  RCN→(ii)H3O+(i)SnCl2+HClRCHO\;\mathrm{RCN}\xrightarrow[(ii)\mathrm{H}_3\mathrm{O}^+]{(i)\mathrm{SnCl}_2+\mathrm{HCl}}\mathrm{RCHO}
(iii) CH3COOHCHCl2/p2∣ClCOOH\mathrm{CH}_3\mathrm{COOH}\overset{\mathrm{Cl}_2/\mathrm{p}}{\mathrm{CH}}\underset{\mathrm{Cl}}{\underset{\vert}{_2}}\mathrm{COOH} CHKOH(Aq)2∣OHCOOH\overset{\mathrm{KOH}(\mathrm{Aq})}{\mathrm{CH}}\underset{\mathrm{OH}}{\underset{\vert}{_2}}\mathrm{COOH}
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