ECAT Pre Engineering Chemistry Chapter 23 MCQ Test With Answer

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

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

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

The addition of HCN to carbonyl compounds is an example of

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

On heating acetaldehyde with ammonical silver nitrate solution, we get

• CH₃OH A
• Silver acetate B
• HCHO C
• Silver mirror 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 of the following will have the highest boiling point

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

Ketones are reduced to

• Primary alcohol A
• Secondary alcohol B
• Tertiary alcohol C
• All of these 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 catalytic prmoter used for the industrial preparation of acetaldehyde is

• PdCI₂ A
• CuCI₂ B
• Pd + CaCI₂ C
• None 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

Formalin is an aqueous solution of

• Furfural A
• Fluorescein B
• Formaldehyde C
• Formic acid D

The color of ppts formed by Benedirct's test is

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

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

Which of these reactions is shown by buranone, CH₃COCH₂CH₃

• On warming with acidified potassium dichromative (IV) the solution turns green A
• On heating with Fehling's reagent a red precipitate is formed B
• With 2,4-dinitrophenlhydrazine reagent an orange precipitate is formed C
• With hydrogen cyanide an aldehyde is formed D

Ketons are prepared by the oxidation of

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

Aledehydes ketones can be prepared form alcohols by their:

• Reduction A
• Oxidation B
• Decomposition C
• Synthesis D

Which is mild oxidizing agent ?

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

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

• 
  A
• 
  B
• 
  C
• 
  D

The colour of ppts formed by Fehling's test is

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

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 of the following in incorrect?

• FelCl₃is used in the detection of phenols A
• Fehling solution is used in the detection of glucose B
• Tollen's reagent is used in detection of unsaturation C
• NaHSO₃is used in the detection of carbonyl compounds 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 can be distinguished from ketones by

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

Which of the following is hypnotic?

• Acetaldehyde A
• Metaldehyde B
• Paraldehyde C
• None D

Which reaction yields Bakelite?

• Urea with HCHO A
• Tetramethyl glycol with Hezamethylene diisocyanate B
• Phenol and HCHO C
• Ethylene glycol and Dimethylterephthalate D

Aldehydes are reduced to :

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

Which reagent will distinguish a ketone from an aldehyde

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

Reduction of aldehydes with HI and P gives

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

Which of the following reagents is used to distinguish acetone and acetophenone

• NaHSO₃ A
• Grinard reagent B
• Na₂SO₄ C
• NH₄Cl D

Aniline reacts with which of these to form Schiff base?

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