The Total solution for NCERT class 6-12
Classify the following as primary, secondary and tertiaryalcohols:
Answer - 1 : -
Primary alcohol → (i), (ii), (iii)
Secondary alcohol → (iv), (v)
Tertiary alcohol → (vi)
Identify allylic alcohols in the above examples.
Answer - 2 : -
The alcohols given in (ii) and (vi) are allylic alcohols.
Name the following compounds according to IUPAC system.
Answer - 3 : -
(i) 3-Chloromethyl-2-isopropylpentan-1-ol
(ii) 2,5-Dimethylhexane-1, 3-diol
(iii) 3-Bromocyclohexanol
(iv) Hex-1-en-3-ol
(v) 2-Bromo-3-methylbut-2-en-1-ol
Show how are the following alcohols prepared by thereaction of a suitable Grignard reagent on methanal?
Answer - 4 : -
(i)
(ii)
Write structures of the products of the followingreactions:
Answer - 5 : -
Give structures of the products you wouldexpect when each of the following alcohol reacts with (a) HCl-ZnCl2 (b)HBr and (c) SOCl2.
Answer - 6 : -
(i) Butan-1-ol
(ii) 2-Methylbutan-2-ol
Answer
(a)
Primary alcohols do not react appreciablywith Lucas’ reagent (HCl-ZnCl2) at room temperature.
Tertiary alcohols react immediately with Lucas’ reagent.
(b)
(c)
Predict the major product of acid catalysed dehydration of
Answer - 7 : -
(i) 1-Methylcyclohexanol and
(ii) Butan-1-ol
Ortho and para nitrophenolsare more acidic than phenol. Draw the resonance structures of the correspondingphenoxide ions.
Answer - 8 : -
Resonance structure of the phenoxide ion
Resonance structures of p-nitrophenoxideion
Resonance structures of o-nitrophenoxideion
It can be observed that the presence of nitro groupsincreases the stability of phenoxide ion.
Write the equations involved in the following reactions:
(i) Reimer-Tiemannreaction
(ii) Kolbe’sreaction
Answer - 9 : -
1. Reimer–Tiemann reaction
2. Kolbe’s reaction
Write the reactions of Williamson synthesis of2-ethoxy-3-methylpentane starting from ethanol and 3-methylpentan-2-ol.
Answer - 10 : -
In Williamson synthesis, an alkyl halidereacts with an alkoxide ion. Also, it is an SN2reaction. In the reaction, alkyl halides should be primary having the leaststeric hindrance. Hence, an alkyl halide is obtained from ethanol and alkoxideion from 3-methylpentan-2-ol.