ECAT Pre Engineering Chemistry Chapter 23 MCQ Test With Answer

In aldol condensation reaction, a double bond is formed between ______ and ______ carbon atoms

• αandβ A
• αandα B
• αand Y C
• None of these D

Which compound would undergo nucleophilic addition

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

On heating acetaldehyde with ammonical silver nitrate solution, we get

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

Cyanohydrin of which of the following forms lactic acid

• HCHO A
• CH₃COCH₃ B
• CH₃CHO C
• CH₃CH₂CH₂CHO D

Which reaction is of condensation or addition elimination reaction?

• Ketol A
• Aldol B
• Cannizzaro C
• All of these D

Aldehydes give reactions :

• Oxidation and reduction A
• Base-catalysed nucleophilic B
• Acid catalysed nucleophilic C
• All of these D

Acetal is produced by reacting alcohol in the presence of dry HCl with

• Acetaldehyde A
• Ketone B
• Ether C
• Carboxylic acid D

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

Acetaldehyde is used to make

• Rubbber A
• Antiseptics B
• Phenolic resin C
• All of these D

Tollen's reagent is

• Ammonical cuprous chloride A
• Ammonical cuprous oxide B
• Ammonical silver bromide C
• Ammonical silver nitrate 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

A compound possessingα-hydrogen atom, in the presence of dilute alkali formsβ-hydroxy aldehyde. This product on heating with dilute acid forms an unsaturated crotonaldehyde. The compound is

• CH₃CHO A
• CH₃CH₂CHO B
• CH₂= CH - CHO C
• HC = C - CHO D

The color of ppts formed by Fehling's test is

• Brick red A
• Red B
• Yellow C
• Orange D

Which of the following react with NaOH to produce an acid and an alcohol?

• NCHO A
• CH₃COOH B
• CH₃CH₂COOH C
• C₆H₅COOH D

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

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

Formaline Contains ______% alcohol

• 80 A
• 37 B
• 8 C
• 52 D

Chromic acid used to oxidize

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

Which of the following will have the highest boiling point?

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

An organic compound 'A' has the molecular formula C₃H₆O, it undergoes iodoform test. When saturated with HCl it gives 'B' of molecular formula C₉H₁₄O. A and B, respectively are

• Propanal and mesitylene A
• Propanone and mesityl oxide B
• Propanone and 2, 6-dimethyl-2,5-heptadien-4-one C
• Propanone and mesitylene oxide 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

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

In which reaction, aromatic aldehyde is treated with acid anhydride in the presence of corresponding salt of the acid to give unsaturated aromatic acid?

• Friedel-Crafts reaction A
• Perkin's reaction B
• Wurtz reaction C
• None of these D

On adding sodium nitroprusside ketones give

• Red A
• Wine red B
• White C
• Orange D

Hydrogenation of bezoyl chloride in presence of Pd on BaSO₄gives

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

The colour of ppts formed by Fehling's test is

• Brick red A
• Red B
• Yellow C
• Orange 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

The product of the reaction between propanone and HCN is hydrolysed under acidic conditions. What is the formula of the final product

• CH₃CH(OH)COOH A
• CH₃CH₂CH(OH)COOH B
• (CH₃)₂C(OH)COOH C
• CH₃CH₂CH₂COOH D