--%>
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 : Solubility of a gas The solubility of a

    The solubility of a gas in water depends on: (a) Nature of the gas (b) Temperature (c) Pressure of the gas (d) All of the above. Can someone help me in finding out the right answer.

    		•
  • Q : Relative reactivity Which is more

    Which is more reactive towards nucleophilic substitution aryl halide or vinyl halides

    		•
  • Q : Problem on decinormal strength Can

    Can someone please help me in getting through this problem. How many grams of dibasic acid (having mol. wt. 200) must be present in 100ml  of its aqueous solution to provide decinormal strength: (i) 1g  (ii)2g  (iii) 10g  (iv) 20g<

    		•
  • Q : Relative lowering of vapour pressure

    Which of the following solutions will have a lower vapour pressure and why? a) A 5% aqueous solution of cane sugar. b) A 5% aqueous solution of urea.

    		•
  • Q : Microwave Adsorption The absorption of

    The absorption of microwave radiation increases the rotational energy of molecules and gives information about the moment of inertia of the molecules.Now we can begin the study of the spectroscopy that explores the different ways in which the energy of the

    		•
  • Q : Calculate PH value for a acetic acid 1.

    1. A solution of 0.100 M acetic acid is prepared. a) What is its pH value? b) If 20% of the initial acetic acid is converted to the acetate form by titration with NaOH, what is the resultant pH?

    		•
  • Q : Finding Normality Can someone please

    Can someone please help me in getting through this problem. Concentrated H2SO4 has a density of 1.98 gm/ml and is 98% H2SO4 by weight. The normality is: (a) 2 N  (b) 19.8 N  (c) 39.6 N  (d) 98

    		•
  • Q : Cations Chromium(III) hydroxide is

    Chromium(III) hydroxide is highly insoluble in distilled water but dissolves readily in either acidic or basic solution. Briefly explain why the compound can dissolve in acidic or in basic but not in neutral solution. Write appropriate equations to support your answer

    		•
  • Q : Latent heat of vaporization Normal

    Normal butane (C4H10) is stored as a compressed liquid at 90°C and 1400 kPa. In order to use the butane in a low-pressure gas-phase process, it is throttled to 150 kPa and passed through a vaporizer. The butane emerges from the vaporizer as a

    		•
  • Q : Anti-aromatic and the non-aromatic

    What is main difference among anti-aromatic and the non-aromatic compounds?

    		•