--%>
Assignment Help - homework help

What is cannizaro reaction? Explain with example.

Aldehydes which do not have 606_amines with aldehydes3.png -hydrogen atom, such as formaldehyte and benzaldehyte, when heated with concentrated (50%)alkali solution, give a mixture of alcohol and the salt of a carboxylic acid.
1587_cannizaro reaction.png 
In this reaction, the aldehyde undergoes disproportionate. It implies that one molecule of aldehydes is oxidized to carboxylic acid and the other is reduced to alcohol. Ketones do not provide this reaction.
 The reaction is also possible in all compounds which lack 606_amines with aldehydes3.png -hydrogen atom. For example,

1131_cannizaro reaction1.png 


It must be noted that in crossed Cannizzaro's reaction, when an aldehydes is treated with formaldehyde and aqueous basic solution then it is formaldehyde that undergoes oxidation.
2028_cannizaro reaction2.png 

Compounds containing two carbonyl groups undergo internal Cannizzaro's reaction.
738_cannizaro reaction3.png 
On the other hand, aldehydes containing 606_amines with aldehydes3.png -hydrogen atoms when heated with concentrated alkali give brown resinous mass.
1335_cannizaro reaction4.png

   Related Questions in Chemistry

  • Q : Molarity of HCl solution 20 ml of HCL

    20 ml of HCL solution needs 19.85 ml of 0.01M NaOH solution for complete neutralization. Morality of the HCL solution is:  (i) 0.0099 (ii) 0.099 (iii) 0.99 (iv) 9.9 Choose the right answer from above.

    		•
  • Q : Explain the mechanism of Enzyme

    A mechanism for enzyme-catalyzed reactions that leads to the typical rate equation for these reactions can be described.A variety of rate equations are required to portray the rates of enzymes catalyzed reagents and physical conditions that are encountered

    		•
  • Q : Can protein act as the buffer Can

    Can protein act as the buffer? Briefly comment on that statement.

    		•
  • Q : Procedure for separating the components

    Briefly describe the procedure for separating the components of the gun-powder?

    		•
  • Q : Volume of solution containing solute

    What volume of solution contains 0.1 mole of the solute: (a) 100ml (b) 125ml  (c) 500ml (d) 62.5ml Choose the right answer from above.

    		•
  • Q : How haloalkanes are prepared from

    Alkyl halides can be prepared from alkanes through substitution and from alkenes through addition of halogen acids or through allylic substitution.    From alkanesWhen alkanes are treated with halogens, chlo

    		•
  • Q : Describe Transformation Matrices. Each

    Each symmetry operation can be represented by a transformation matrix.You have seen what happens when a molecule is subjected to the symmetry operation that corresponds to any of the symmetry elements of the point group to which the molecule belongs. The m

    		•
  • Q : Kinds of insulators Describe all the

    Describe all the kinds of insulators which are present?

    		•
  • Q : What is Elevation in boiling point? The

    The boiling of a liquid may be defused by the temperature at which its vapour pressure which is equal to atmospheric pressure. The effect of addition in a non-volatile solute on the boiling point shown and its solution containing non-volatile solute with tempe

    		•
  • Q : Why acetic has less conductivity than

    Illustrate the reason, why acetic has less conductivity than Hcl?

    		•