ECAT Pre Engineering Chemistry Chapter 23 MCQ Test With Answer

The base used in Cannizzaro's reaction is

• NaOH A
• KOH B
• CHI₃ C
• All of these D

Which of the following reactions is used for detecting presence of carbonyl group?

• Reaction with hydroxylamine A
• Reaction with hydrazine B
• Reaction with phenyl hydrazine C
• All D

Ethanal may be converted into a three-carbon acid in a two-step process.

Which compound is the intermediate

• CH₃CO₂H A
• CH₃CN B
• CH₃CH₂CN C
• CH₃CH(OH)CN D

Acetone reacts with HCN to form a cyanohydrin. It is an example of

• Electrophilic addition A
• Electrophilic substitution B
• Nucleophilic addition C
• Nucleophilic substitution D

For which one of the following pairs of compounds can the members be distinguished by means of Tollen's test

• HCHO and CH₃CHO A
• CH₃CHO and CH₃COCH B
• CH₃COCH₃and C₆H₅COCH₃ C
• CH₃COOH and CH₃COOCH₃ D

• Br_2(aq) A
• 2, 4-dinitrophenylhydrazine B
• NaBH C
• Tollen's reagent D

Wolf-kishner reduction is used for the reduction of

• Nitro compounds A
• Carboxylic acids B
• Carbonyl compounds C
• Olefins D

Silver mirror test is applied for

• Aldehydes A
• Alcohols B
• Acids C
• Esters D

Which of the following compounds does not react with NaHSO₃?

• C₆H₅CHO A
• Acetophenone B
• Acetone C
• Acetaldehyde D

A compound R has all of the following properties. It is neutral; It gives an orange precipitate with 2,4-dinitrophenythydrazine; it evolves hydrogen chloride when treated with PCI₅in the cold What could R be

• 
  A
• 
  B
• 
  C
• 
  D

Aldehydes which do not haveα-hydrogen undergo

• Aldol combination A
• Cannizzaro's reaction B
• Substitution C
• Elimination D

Which of the following will have the highest boiling point?

• Methanal A
• Ethanal B
• Propanal C
• 2-Hexanone D

Chromic acid used to oxidize

• Aldehyde A
• Ketone B
• Both a and b C
• None of these D

What is formed when propanone is refluxed with an anhydrous solution of NaBH₄

• Propanal A
• Propan-1-ol B
• Propan-2-ol C
• Propane D

A compound A has a molecular formula C₂Cl₃OH. It reduces Fehling solution and on oxidation produces a monocarboxylic acid B.A can also be obtained by the action of Cl₂on Ethanol. A is

• Chloral hydrate A
• CHCl₃ B
• CH₃Cl C
• Chloroacetic acid D

Which one of the following reagents will distinguish between C₆H₅CHO and C₆H₅COCH₃

• Aqueous bromine A
• Phosphorus pentachloride B
• 2, 4 DNPH C
• Tollen's reagent D

Hydroxyl amine is a derivative of::

• Alcohol A
• Aldehyde B
• Ammonia C
• Ketone D

Dehydration of allcohol gives:

• Alkane A
• Alkene B
• Aldehyde C
• ketone D

The carbon of a carbonyl group is:

• sp hybridized A
• sp² hybridized B
• sp³ Hybidized C
• None of these D

Which of the following compounds will react with reagent ?

• CH₃ CO H A
• CH₃ CO CH₃ B
• CH_{3 COOH} C
• CH₃ CO CH₂CH₃ D

C₂H₅CHO and (CH₃)₂CO can be distunguished by testing with

• Phenyl hydrazine A
• Hydroxylamine B
• Fehling solution C
• Sodium bisulphate D

In 1903 Arthur Lapeworth became the first chemist to investigate a reaction mechanism. The reaction he investigated was that of hydrogen cyanide with propanone. What do we now call the mechanism of this reaction

• Electrophilic addition A
• Electrophilic substitution B
• Nucleophilic addition C
• Nucleophilic substitution D

Reaction of Grignard's reagent eith aldehyds other formaldehyde gives: Reaction of Grignard's reagent with formaldehyde gives:

• Pri-alcohol A
• Sec-alcohol B
• Ter-alcohol C
• Carboxylic D

Cannizzzaro's reaction is not given by:

• Formaldehyde A
• Acetaldehyde B
• Benzaldehyde C
• Trimethyl D

Which alcohol may be oxidised to a product which react with 2,4-dinitorphenylhydrazine reagent but not with Fehling's reagent

• Butan-1-ol A
• Butan-2-ol B
• 2-methylpropan-1-ol C
• 2-methylpropan-2-ol D

During the mechanism of aldol condensation a/an ______ is formed

• Oxide A
• Alkali B
• Alkoxide ion C
• None of these D

Aldelydes are the oxidation product of

• P-alcohols A
• s-alcohols B
• ter-alcohols C
• carboxylic acids D

Aldehydes and ketones are carbonyl compounds. Which of them react both with NaBH₄and with Tollen's reagent

• Both aldehydes and ketones A
• Aldehydes only B
• Ketones only C
• Neither aldehydes nor ketones D

Formalin is:

• 10% solution of formaldehyde in water A
• 20% solution of formaldehyde in water B
• 40% solution of formaldehyde in water C
• 60% solution of formaldehyde in water D

The catalytic prmoter used for the industrial preparation of acetaldehyde is

• PdCI₂ A
• CuCI₂ B
• Pd + CaCI₂ C
• None of these D