ECAT Pre Engineering Chemistry Chapter 23 MCQ Test With Answer

Ketons are prepared by the oxidation of

• Primary alcohol A
• Secondary alcohol B
• Tertiary alcohol C
• None of these D

On heating acetaldehyde with ammonical silver nitrate solution, we get

• CH₃OH A
• Silver acetate B
• HCHO C
• Silver mirror D

The homologous series of aldehydes and ketones have general formula:

• C_nH_2nO A
• C_nH_nO B
• C_nH_2n-1O C
• C_nH_nO_n 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

In formadaldehyde and KOH are heated then we get

• Acetylene A
• Methane B
• Methyl alcohol C
• Ethyl formate D

Reduction of aldehydes with HI and P gives

• Primary alcohols A
• Secondary alcohols B
• Alkanes C
• Tertiary alcohols 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

Formaldehyde is used to make

• Plastics A
• Medicine B
• Antiseptic C
• All of these D

• 2-chlorobutanal A
• alfa-chlorobutanal B
• 2-chlorobutyraldehyde C
• alfa- chlorobutyraldehyde 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

Aldehydes are oxidizes are to give:

• Primary alcohol A
• Sec-alcohol B
• Ter-alcohol C
• Carboxylic acid D

Aldehydes which do not haveα-hydrogen undergo

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

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

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

Hydrogenation of bezoyl chloride in presence of Pd on BaSO₄gives

• Benzyl alcohol A
• Benzaldehyde B
• Benzoic acid C
• Phenol D

• Treatment with HCN followed by acid hydrolysis A
• Oxidation of acetaldehyde followed by basic hydrolysis B
• Treatment with HCN followed by reduction C
• Treatment with HCN followed by oxidation D

Which reagent could be used to distinguish between CH₃CH(OH)CH₂CHO and CH₃COCH₂CH₂OH

• Acidified potassium dichromate A
• Dilute sulphuric acid B
• 2,4-dinitrophenylydrazine C
• Fehling's reagent D

Aldol condensation is actually

• Electrophilic addition of carbonation A
• Electrophilic addition of carbonium ion B
• Nucleophilic addition of carbonation C
• Nuclephilic addition of carbonium ion D

Condensation of aldeydes withα-hydrogen gives:

• Acetal A
• Ketal B
• Aldol C
• Cannizzaro product D

Aniline reacts with which of these to form Schiff base?

• Acetic acid A
• Bezaldehyde B
• Acetone C
• NH₃ D

Compounds X, Y and Z, all react with PCI₅to release hydrogen chloride, but only one of them reacts eith 2,4-dinitrophenylhydrazine reagent. Which one of the following combinations could be X, Y and Z

• 
  A
• 
  B
• 
  C
• 
  D

Aldehyde and small methyl ketones form crystalline ______ ppts with saturated sodium bisulphate solution

• White A
• Red B
• Yellow C
• None of these D

The addition of HCN to carbonyl compounds is an example of

• Nucleopihlic substituion A
• Electrophilic addition B
• Nueleophilic addition C
• Electrophilic substitution D

Which is not true about acetophenone?

• Reacts to form 2,4-dintrophenyl hydrazine A
• Reacts with Tollen's reagent to form silver mirror B
• Reacts with I₂/NaOH to form iodoform C
• On oxidation with alkaline KMnO₄followed by hydrolysis gives benzoic acid D

Which one of the following is a product of the reaction between C₆H₅CH₂OH and CH₃COCI

• C₆H₅OCOCH₃ A
• C₆H₅CH₂CI B
• C₆H₅CH₂OCOCH₃ C
• C₆H₅CH₂COCI 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

Acetone is prepared by

• Oxidation of n-propyl alcohol A
• Oxidation of acetaldehyde B
• Pyrolysis of calcium acetate C
• Pyrolysis of calcium acetate as well as acetic acid 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

At room temperature formaldehyde is

• Gas A
• Liquid B
• Solid C
• None of the above D

Which compound would undergo nucleophilic addition

• Ethene, C₂H₄ A
• Bromoethane, C₂H₅Br B
• Ethanal, CH₃CHO C
• Ethane, C₂H₆ D

Which compound on reaction with hydrogen cyanide produces a compound with a chiral centre

• Ch₃CHO A
• CH₃CH₂COCH₂CH₃ B
• CH₃CO₂CH₃ C
• HCHO D