English
Karnataka Board PUCPUC Science 2nd PUC Class 12

Assertion: Aromatic aldehydes and formaldehyde undergo Cannizaro reaction. Reason: Aromatic aldehydes are almost as reactive as formaldehyde.

Advertisements
Advertisements

Question

Assertion: Aromatic aldehydes and formaldehyde undergo Cannizaro reaction.

Reason: Aromatic aldehydes are almost as reactive as formaldehyde.

Options

  • Assertion and reason both are correct and reason is correct explanation of assertion.

  • Assertion and reason both are wrong statements.

  • Assertion is correct statement but reason is wrong statement.

  • Assertion is wrong statement but reason is correct statement.

  • Assertion and reason both are correct statements but reasson is not correct explanation of assertion.

MCQ
Advertisements

Solution

Assertion is correct statement but reason is wrong statement.

Explanation:

There is no alpha hydrogen atom in the Cannizaro process. Formaldehyde and aromatic aldehydes do not contain alpha hydrogen. It proceeds through the Cannizaro reaction. Formaldehyde is the most reactive of all aldehydes.

shaalaa.com
  Is there an error in this question or solution?
Chapter 12: Aldehydes, Ketones and Carboxylic Acids - Multiple Choice Questions (Type - I) [Page 176]

APPEARS IN

NCERT Exemplar Chemistry Exemplar [English] Class 12
Chapter 12 Aldehydes, Ketones and Carboxylic Acids
Multiple Choice Questions (Type - I) | Q 45 | Page 176

RELATED QUESTIONS

How will you convert ethanal into the following compound?

Butane-1, 3-diol


How will you convert ethanal into the following compound?

But-2-enal


Describe the following:

Cross aldol condensation


Complete the synthesis by giving missing starting material, reagent or product.

\[\begin{array}{cc}
\ce{C6H5CHO}\phantom{............}\\
\phantom{........}\ce{+\phantom{......}\ce{->[dil.NaOH][\Delta]}}\phantom{...}\\
\ce{CH3CH2CHO}\phantom{............}
\end{array}\]


Write chemical equations of the following reaction : 

Propanone is treated with dilute Ba (OH)2-.


Write a chemical equation for the following reaction: 
Propanone is treated with dilute Ba( OH)2.


Which product is formed when the compound  is treated with concentrated aqueous \[\ce{KOH}\] solution?


Compounds A and C in the following reaction are:

\[\ce{CH3CHO ->[(i) CH3MgBr][(ii) H2O] (A) ->[H2SO4, Δ] (B) ->[Hydroboration oxidation] (C)}\]


Which of the following compounds do not undergo aldol condensation?

(i) \[\ce{CH3 - CHO}\]

(ii)  

(iii)  \[\begin{array}{cc}
\phantom{}\ce{O}\\
\phantom{}||\\
\ce{CH3 - C - CH3}
\end{array}\]

(iv) \[\begin{array}{cc}
\phantom{}\ce{CH3}\\
|\phantom{...}\\
\ce{CH3 - C - CHO}\phantom{..}\\
|\phantom{...}\\
\phantom{}\ce{CH3}\\
\end{array}\]


Why is there a large difference in the boiling points of butanal and butan-1-ol?


Assertion: The α-hydrogen atom in carbonyl compounds is less acidic.

Reason: The anion formed after the loss of α-hydrogen atom is resonance stabilised.


When liquid ‘A’ is treated with a freshly prepared ammoniacal silver nitrate solution, it gives bright silver mirror. The liquid forms a white crystalline solid on treatment with sodium hydrogensulphite. Liquid ‘B’ also forms a white crystalline solid with sodium hydrogensulphite but it does not give test with ammoniacal silver nitrate. Which of the two liquids is aldehyde? Write the chemical equations of these reactions also.


Cross aldol condensation occurs between


Convert the following:

Acetaldehyde to But-2-enal


The major product of the following reaction is:


Assertion (A): The final product in Aldol condensation is always α, β-unsaturated carbonyl compound.

Reason (R): α, β-unsaturated carbonyl compounds are stabilised due to conjugation.


What is aldol condensation? Explain it with suitable examples.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×