ECAT Pre Engineering Chemistry Chapter 23 MCQ Test With Answer

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

Aldehydes give reactions :

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

Aldehydes can be distinguished from ketones by

• 2,4-DNPH test A
• NaHSO₃test B
• N₂H₄test C
• Tollen's test D

Give IUPAC name fo Acetone

• Ethanal A
• Propanone B
• Butanone C
• Propanal D

Common names of aldehydes are given by corresponding:

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

Cannizzaro reaction is not given by

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

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

Reductive ozonolysis of benzene produces

• Acetone A
• Maleic anhydride B
• Phthalic acid C
• Glyoxal D

The carbon atom of a carbonyl group is

• Sp hybridized A
• Sp²hybridized B
• Sp³hybridized C
• None of these D

A nucleophilic reagent will readily Attack

• Ethylene A
• Ethanal B
• Ethanol C
• Ethylamine D

Which reaction is of condensation or addition elimination reaction?

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

Wolf-kishner reduction is used for the reduction of

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

Which is mild oxidizing agent ?

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

The catalytic prmoter used for the industrial preparation of acetaldehyde is

• PdCI₂ A
• CuCI₂ B
• Pd + CaCI₂ 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

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

Which reagent will distinguish a ketone from an aldehyde

• Br₂ A
• 2, 4-dinitrophenylhydrazine B
• NaBH₄ C
• Tollen's reagent D

Benzophenone can be converted into benzene using

• Fused alkali A
• Anhydrous AlCl₃ B
• Sodium amalgam in water C
• Acidfied dichromate D

• Q and R Q and R A
• R only Q and R B
• Q and R R only C
• Q only R only D

Which of the following will have the highest boiling point

• Methanol A
• Ethanol B
• Propanal C
• 2-hexanone D

A food chemist wants to create the odour of pineapples for a product. An ester with this odour has the formula C₃H₇COOC₂H_5.Which pair of reagents would produce this ester

• C₂H₅CI and C₃H₇COOH A
• C₂H₅OH and C₃H₇CONH₂ B
• C₂H₅OH and C₃H₇COOH C
• C₃H₇OH and C₂H₅COCI D

Which of the following alcohols cannot be produced by treatment of aldehydes or ketones with NaBH₄or LiAIH₄?

• 1-propanol A
• 2-propanol B
• 2-Methyl-2-propanol C
• Ethanol D

The addition of HCN to carbonyl compounds is an example of

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

Aldehydes which do not haveα-hydrogen undergo

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

Aldehydes are reduced to :

• Pri-alcohol A
• Sec-alcohol B
• Ter-alcohol C
• All of these D

Which isomer of C₅H₁₁OH gives, one dehydration, the greastest number of different alkenes

• 
  A
• 
  B
• 
  C
• 
  D