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

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

Advertisements
Advertisements

प्रश्न

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

टीपा लिहा
Advertisements

उत्तर

Butan-1 -ol has higher boiling point (391 K) than butanal due to intermolecular hydrogen bonding between –OH groups of alcohols.

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 12: Aldehydes, Ketones and Carboxylic Acids - Multiple Choice Questions (Type - I) [पृष्ठ १७२]

APPEARS IN

एनसीईआरटी एक्झांप्लर Chemistry [English] Class 12
पाठ 12 Aldehydes, Ketones and Carboxylic Acids
Multiple Choice Questions (Type - I) | Q 19 | पृष्ठ १७२

संबंधित प्रश्‍न

Which of the following compounds would undergo aldol condensation, which the Cannizzaro reaction and which neither? Write the structures of the expected products of aldol condensation and Cannizzaro reaction.

  1. Methanal
  2. 2-Methylpentanal
  3. Benzaldehyde
  4. Benzophenone
  5. Cyclohexanone
  6. 1-Phenylpropanone
  7. Phenylacetaldehyde
  8. Butan-1-ol
  9. 2, 2-Dimethylbutanal

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.


Describe the following:

Cross aldol condensation


Write chemical equations of the following reaction :
Benzoyl chloride is hydrogenated in the presence of `"Pd"/(BaSO_4)`


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


Which of the following conversions can be carried out by Clemmensen Reduction?

(i) Benzaldehyde into benzyl alcohol

(ii) Cyclohexanone into cyclohexane

(iii) Benzoyl chloride into benzaldehyde

(iv) Benzophenone into diphenyl methane


Why are carboxylic acids more acidic than alcohols or phenols although all of them have hydrogen atom attached to a oxygen atom \[\ce{(-O-H)}\]?


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.


Assertion: Aromatic aldehydes and formaldehyde undergo Cannizaro reaction.

Reason: Aromatic aldehydes are almost as reactive as formaldehyde.


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


Predict the reagent for carrying out the following transformations:

Ethanal to 3-hydroxy butanal


Explain Aldol condensation of ethanal.


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?

Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×