मराठी
कर्नाटक बोर्ड पी.यू.सी.पीयूसी विज्ञान 2nd PUC Class 12

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

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प्रश्न

Assertion: Aromatic aldehydes and formaldehyde undergo Cannizaro reaction.

Reason: Aromatic aldehydes are almost as reactive as formaldehyde.

पर्याय

  • 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
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उत्तर

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.

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पाठ 12: Aldehydes, Ketones and Carboxylic Acids - Multiple Choice Questions (Type - I) [पृष्ठ १७६]

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एनसीईआरटी एक्झांप्लर Chemistry Exemplar [English] Class 12
पाठ 12 Aldehydes, Ketones and Carboxylic Acids
Multiple Choice Questions (Type - I) | Q 45 | पृष्ठ १७६

संबंधित प्रश्‍न

Write the products formed when CH3CHO reacts with the following reagents: CH3CHO in the presence of dilute NaOH


Write structural formulas and names of four possible aldol condensation products from propanal and butanal. In each case, indicate which aldehyde acts as nucleophile and which as electrophile.


How will you bring about the following conversion in not more than two steps?

Benzaldehyde to 3-Phenylpropan-1-ol


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

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


Give reasons  Acetylation of aniline reduces its activation effect.


Write chemical equations of the following reaction : 

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


What is substituted imine called?


Explain aldol condensation reaction in detail.


Compounds A and C in the following reaction are:

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


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


What product will be formed on reaction of propanal with 2-methylpropanal in the presence of \[\ce{NaOH}\]? What products will be formed? Write the name of the reaction also.


Compound ‘A’ was prepared by oxidation of compound ‘B’ with alkaline \[\ce{KMnO4}\]. Compound ‘A’ on reduction with lithium aluminium hydride gets converted back to compound ‘B’. When compound ‘A’ is heated with compound B in the presence of \[\ce{H2SO4}\] it produces fruity smell of compound C to which family the compounds ‘A’, ‘B’ and ‘C’ belong to?


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.


Cross aldol condensation occurs between


Convert the following:

Acetaldehyde to But-2-enal


Predict the reagent for carrying out the following transformations:

Ethanal to 3-hydroxy butanal


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.


When acetaldehyde is treated with dilute NaOH, the following reaction is observed.

\[\begin{array}{cc}
\ce{2CH3 - CHO ->[dil.NaOH] CH3 - CH - CH2 - CHO}\\
\phantom{...............}|\\
\phantom{.................}\ce{OH}
\end{array}\]

  1. What are the functional groups in the product?
  2. Can another product be formed during the same reaction? (Deduce the answer by doing atomic audit of reactant and product).
  3. Is this an addition reaction or condensation reaction?

Write a note on the aldol condensation reaction of acetaldehyde.


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