--%>
Assignment Help - homework help

Explain the preparation of phenols.

The methods used for the preparation of phenols are given below:
    
From aryl sulphonic acids

Aryl sulphonic acids on fusion with NaOH at 573 K followed by acidification yield phenols.

1616_Phenol preparation.png 

From aryl halides (Dow's process)

Phenol is obtained on a large scale by heating chlorobenzene with 10% NaOH solution at about 623 K and under a pressure of 300 atmospheres in the presence of copper catalyst.

1327_Phenol preparation1.png 

From diazonium salts

In the laboratory phenols are prepared hydrolysis of diazonium salts with water or dilute acids.

994_Phenol preparation2.png 
    
By decarboxylation of sodium salt of saclicyclic acid

Phenol can also be obtained by the decarboxylation of sodium salicyclate with soda lime (an equimolar mixture of NaOH and CaO).
                           
289_Phenol preparation3.png 
    
From Grignard's reagent

when oxygen is bubbled through the solution of phenylmagnesium bromide in ether, it forms an addition product which on acidification with dilute acid gives phenol.

1498_Phenol preparation4.png

   Related Questions in Chemistry

  • Q : Question relatede to calculate molarity

    Select the right answer of the question. What is molarity of a solution of HCl that contains 49% by weight of solute and whose specific gravity is 1.41 : (a) 15.25 (b) 16.75 (c) 18.92 (d) 20.08

    		•
  • Q : Degree of dissociation The degree of

    The degree of dissociation of Ca(No3)2 in a dilute aqueous solution containing 14g of the salt per 200g of water 100oc is 70 percent. If the vapor pressure of water at 100oc is 760 cm. Calculate the vapor pr

    		•
  • Q : Mcq Give me answer of this question.

    Give me answer of this question. The normality of 10% (weight/volume) acetic acid is: (a)1 N (b)10 N (c)1.7 N (d) 0.83 N

    		•
  • Q : Significance of the organic chemistry

    Describe some of the significance of the organic chemistry in brief?

    		•
  • Q : Explosions produce carbon dioxide

    Illustrate all the explosions produce carbon dioxide?

    		•
  • Q : Schrodinger equation with particle in a

    Three dimensional applications of the Schrodinger equation are introduced by the particle-in-a-box problem.So far only a one-dimensional problem has been solved by application of the Schrodinger equation. Now the allowed energies and the probability functi

    		•
  • Q : What is Flash Photolysis Reactions.

    An example illustrates the type of mechanism that can be written to explain the development of flash photolysis reactions. Often, as the reactions in the ozone layer of the earth's atmosphere, we are interested in the kinetic behavior of species that are not a

    		•
  • Q : Question based on vapour pressure and

    Benzene and toluene form nearly ideal solutions. At 20°C, the vapour pressure of benzene is 75 torr and that of toluene is 22 torr. The parial vapour pressure of benzene at 20°C for a solution containing 78g of benzene and 46g of toluene in torr is: (a) 50 (b)

    		•
  • Q : Vapour pressure of volatile substance

    Provide solution of this question. According to Raoult's law the relative lowering of vapour pressure of a solution of volatile substance is equal to: (a) Mole fraction of the solvent (b) Mole fraction of the solute (c) Weight percentage of a solute (d) Weight perc

    		•
  • Q : How molecule-molecule collisions takes

    An extension of the kinetic molecular theory of gases recognizes that molecules have an appreciable size and deals with molecule-molecule collisions. We begin studies of elementary reactions by investigating the collisions b

    		•