Chapter Chosen

Alcohols, Phenols and Ethers

Book Chosen

Chemistry II

Subject Chosen

Chemistry

Book Store

Download books and chapters from book store.
Currently only available for.
CBSE Gujarat Board Haryana Board

Previous Year Papers

Download the PDF Question Papers Free for off line practice and view the Solutions online.
Currently only available for.
Class 10 Class 12
Ortho and para nitrophenols are more acidic than phenol. Draw the resonance structures of corresponding phenoxide ions.

The electron withdrawing groups are more effective in increasing the acidic strength at the para-position relative to the ortho position because of greater dispersal of charge on oxygen atom.

Resonance structure of phenoxide ion:



Resonance structure of paranitrophenol:


Resonance structures of ortho nitro phenol:


Thus, presence of nitro group at ortho and para position incerease the acidic character.

348 Views

Write the equations involved in the following reactions:
(i) Reimer-Tiemann reaction        
(ii) Kolbe’s reaction.


(i) Reimer-Tiemann reaction:



(ii) Kolbe’s reaction:





632 Views

Give the equations of reaction for the preparation of phenol from cumene.


Cumene is oxidised into cumene hydro peroxide by air at high pressure which on decomposition by aqueous acid gives phenol and acetone.




The cumene required in the above reaction is prepared from benzene and propene by Friedel-crafts reaction.



674 Views

Give structures of the products you would expect when each of the following alcohol reacts with,
(a) HCl—ZnCl2 (b) HBr and (c) SOCl2.
(i)  Butan-1-ol      (ii) 2-Methyl butan-2-ol.

(HCl—ZnCl2) is lucas reagent, lucas reagent react with alcohol however it does not react with primary alcohol but readily gives turbidity with tertiary alcohols.

a) Reaction with (HCl—ZnCl2):

Butan-1-ol is primary alcohol thus no reaction occur.
where as 2-methyl butan-2-ol is tertiary alcohol, it forms 2-chloro-2-methylbutane.

 
b) Reaction with HBr:



c) Reaction with SOCl2:

453 Views

(a) Draw the structures of all isomeric alcohols of molecular formula C5H12O and give their IUPAC names.
(b) Classify the isomers of alcohols in the above part of question as primary, secondary and tertiary alcohols.   

(a) Eight isomeric alcohols are possible:





b)  Primary alcohol: pentan-1-ol; methylbutan-1-ol; 3-methyl-1-ol; 2,2Dimethylpropan-1-ol.

Secondary alcohol: Pentan-2-ol; 3-methylbutan-2-ol; pentan-3-ol

Tertiary alcohol: 2-methylbutan-2-ol

 
1743 Views

Write the mechanism of hydration of ethene to yield ethanol.


The mechanism  of the reaction involves the following three step:

Step 1: Proptonation of ethene to form carbocation by electrophilic attack of H3O+.



Step 2: Nucleophilic attack of water on carbocation.



Step 3: Deprotonation to form an ethanol.




 
682 Views