--%>

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 : Diffusion Molecular View When the

    When the diffusion process is treated as the movement of particles through a solvent the diffusion coefficient can be related to the effective size of diffusing particles and the viscosity of the medium.To see how the experimental coefficients can be treat

  • Q : Problem on decinormal Select the right

    Select the right answer of the question. How much water is required to dilute 10 ml of 10 N hydrochloric acid to make it exactly decinormal (0.1 N): (a) 990 ml (b) 1000 ml (c) 1010 ml (d) 100 ml

  • Q : Lowering of vapour pressure Help me to

    Help me to go through this problem. Lowering of vapour pressure is highest for: (a) urea (b) 0.1 M glucose (c) 0.1M MgSo4 (d) 0.1M BaCl2

  • Q : Determining mole fraction of water in

    A mixture has 18 g water and 414 g ethanol. What is the mole fraction of water in mixture (suppose ideal behaviour of mixture): (i) 0.1  (ii) 0.4  (iii) 0.7  (iv) 0.9 Choose the right answer from abo

  • 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 : Reducible Representations The number of

    The number of times each irreducible representation occurs in a reducible representation can be calculated.Consider the C2v point group as described or Appendix C. you can see that (1) sum of

  • Q : Calculating number of moles from

    Choose the right answer from following. If 0.50 mol of CaCl2 is mixed with 0.20 mol of Na3PO4, the maximum number of moles of Ca3 (PO2)2 which can be formed: (a) 0.70 (b) 0.50 (c) 0.20 (d) 0.10

  • Q : Explain Ionic Bond with examples. The

    The bonding in ionic molecules can be described with a coulombic attractive term.For some diatomic molecules we take quite a different approach from that used in preceding sections to describe the bonding. Ionic bonds are interpreted in terms of the coulom

  • Q : Calculating total number of moles

    Choose the right answer from following. While 90 gm of water is mixed with 300 gm of acetic acid. The total number of moles will be: (a)5 (b)10 (c)15 (d)20

  • Q : Eutectic Formation In some two

    In some two component, solid liquid systems, a eutectic mixture forms.Consider, now a two component system at some fixed pressure, where the temperature range treated is such as to include formation of one or more solid phases. A simple behavior is shown b