ECAT Pre Engineering Chemistry Chapter 23 MCQ Test With Answer

Which reagent will distinguish a ketone from an aldehyde

• Br₂ A
• 2, 4-dinitrophenylhydrazine B
• NaBH₄ 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

Aniline reacts with which of these to form Schiff base?

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

Cannizzaro's reaction in not given by

• Formaldehyde A
• Acetaldehyde B
• Benzaldyhyde C
• Trimethylacetaldehyde D

A compound R has all of the following properties. It is neutral; It gives an orange precipitate with 2,4-dinitrophenythydrazine; it evolves hydrogen chloride when treated with PCI₅in the cold What could R be

• 
  A
• 
  B
• 
  C
• 
  D

Aldehydes is distinguished from ketones by using

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

In formadaldehyde and KOH are heated then we get

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

Which of the following reagent will react with both aldehyde and ketones?

• Grinard's reagent A
• Tollen's reagent B
• Fehling's reagent C
• Benedict's reagent D

The carbon of a carbonyl group is:

• sp hybridized A
• sp² hybridized B
• sp³ Hybidized C
• None of these D

Which is mild oxidizing agent ?

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

Which of the following compounds will react with Tollen's reagent

• 
  A
• 
  B
• 
  C
• 
  D

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

Which is used for the reduction of aldehydes and ketones

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

Aldehydes are oxidizes are to give:

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

Acetone is oxidized with

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

Acetaldehyde is used to make

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

Reductive ozonolysis of benzene produces

• Acetone A
• Maleic anhydride B
• Phthalic acid C
• Glyoxal 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 can be distinguished from ketones by

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

• 
  A
• 
  B
• 
  C
• 
  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

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

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

• 
  A
• 
  B
• 
  C
• 
  D

Propyne on hydrolysis in presence of H₂SO₄and HgSO₄gives

• Acetaldehyde A
• Acetone B
• Formaldehyde C
• None D

Aldehydes are reduced to :

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

Which of the following compounds will react with reagent ?

• CH₃ CO H A
• CH₃ CO CH₃ B
• CH_{3 COOH} C
• CH₃ CO CH₂CH₃ 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

Formaline Contains ______% alcohol

• 80 A
• 37 B
• 8 C
• 52 D