ECAT Pre Engineering Chemistry Chapter 23 MCQ Test With Answer

Aldehydes which do not haveα-hydrogen undergo

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

Which is used for the reduction of aldehydes and ketones

• NaBH₄ A
• Pt/Pd B
• Ni C
• All of these D

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

• C₆H₅OCOCH₃ A
• C₆H₅CH₂CI B
• C₆H₅CH₂OCOCH₃ C
• C₆H₅CH₂COCI 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

Aldehydes are oxidizes are to give:

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

In carboxyl group the bond between C and oxygen is:

• Sigma bond A
• Single bond B
• Double Bond C
• Triple bond D

Which one of the following statement is wrong regarding differences between aldehydes and ketones

• Aldehydes undergo reduction to form primary alcohols while ketones undergo reduction to form secondary alcohols A
• Aldehydes undergo oxidation to form acids having less number of carbon atoms while ketones undergo oxidation to form acids having same number of carbon atoms B
• Aldehydes give positive silver mirror test while ketones give negative -mirror test C
• Aldehydes can undergo polymerization while ketones cannot undergo polymerizarion D

Clemensen's reduction of ketones is carried out in

• H₂with Pd catalyst A
• Glycol with KOH B
• LiAIH₄in water C
• Zn-Hg with conc. HCl 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

Acetone is oxidized with

• Tollen's reagent A
• Fehling solution B
• Acidic dichromate solution C
• Benedicts solution D

Which of the following organic compounds exhibits positive Fehling test as well as iodoform test?

• Methanal A
• Ethanol B
• Propanone C
• Ethanal D

Common names of aldehydes are given by corresponding:

• Ketone A
• Alcohol B
• Carboxylic acid C
• ester D

Formaldehyde is used to make

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

Which is mild oxidizing agent ?

• Tollen's reagent A
• KMnO₄ / H₂SO₄ B
• K₂Cr₂O₇ / H₂SO₄ C
• HNO₃ D

Aldehydes is distinguished from ketones by using

• Tollen's reagent A
• Benedict reagent B
• Fehling solution C
• All of the above D

Which of the following is halo form

• CHBr₃ A
• CHCI₃ B
• CHI₃ C
• All of these D

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

Cannizzzaro's reaction is not given by:

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

Aromatic aldehydes undergo disproportionation in presence of sodium or potassium hydroxide to give corresponding alcohol and acid. The reaction is known as

• Wurtz reaction A
• Cannizzaro reaction B
• Friedel Craft reaction C
• Claisen reaction 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

Cannizzaro's reaction in not given by

• Formaldehyde A
• Acetaldehyde B
• Benzaldyhyde C
• Trimethylacetaldehyde 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

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

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

Which of the following does not turn Schiff's reagent to pink?

• Formaldehyde A
• Bezaldehyde B
• Aceton C
• Methyl chloride 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

Carboxyl compounds have functional group:

• R-C-X A
• R-CH=O B
• RCOR C
• All D