--%>

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 : Avogadros hypothesis how avogadros

    how avogadros hypothesis used to deduce the atomicity of elementry gases ?

  • Q : Liquid Vapour Free Energies The free

    The free energy of a component of a liquid solution is equal to its free energy in the equilibrium vapour.Partial molal free energies let us deal with the free energy of the components of a solution. We use these free energies, or simpler concentration ter

  • Q : Molar conductance what is the molar

    what is the molar conductance of chloropentaamminecobalt(III) chloride?

  • Q : Explain the molecular mass with respect

    During the formation of polymers, different macromolecules have different degree of polymerisation i.e. they have varied chain lengths. Thus, the molecular masses of the individual macromolecules in a particular sample of the polymer are different. Hence, an average value of the molecular mass is

  • Q : Explain various chemicals associated

    During processing of food, several chemicals are added to it to augment its shelf life and to make it more attractive as well. Main types of food addi

  • Q : Explain vapour pressure of liquid

    Liquid solutions are obtained when the solvent is liquid. The solute can be a gas, liquid or a solid. In this section we will discuss the liquid solutions containing solid or liquid solutes. In such solutions the solute may or may not be volatile. We shall limit our d

  • Q : Forms a molecule to an organic molecule

    Briefly state what forms a molecule to an organic molecule?

  • Q : Molar mass of compound The freezing

    The freezing point of a solution having 4.8 g of a compound in 60 g of benzene is 4.48. Determine the molar mass of the compound (Kf = 5.1 Km-1) , (freezing point of  benzene = 5.5oC)          &n

  • Q : Infrared Adsorption The adsorption of

    The adsorption of infrared radiation by diatomic molecules increases the vibrational energy fo molecules and gives information about the force constant for the "spring" of the molecule.;The molecular motion that has the next larger energy level spacing aft

  • Q : Describe physical adsorption and its

    When the forces of attraction existing between adsorbate and adsorbent are van der Waal's forces, the adsorption is called physical adsorption. This type of adsorption is also known as physisorption or van der Waal's adsorption. Since the forces existing between adsorbent and adsorbate are very w