ECAT Pre Engineering Chemistry Chapter 23 MCQ Test With Answer

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

An organic compound has the following properties ; It gives a positive tri-iodomethane test; it gives a yellow ppt, with 2, 4-DNP regent; it does not react with Tollen's reagent . Which compound would give these results

• CH₃CHO A
• CH₃CH₂OH B
• CH₃CH₂COCH₃ C
• CH₃CH₂CH₂CHO D

Aldehydes are produce in atmosphere by

• Oxidation of secondary alcohols A
• Reduction of alkenes B
• Reaction of oxygen atoms with hydrocarbons C
• Reaction of oxygen atoms with ozone D

C₂H₅CHO and (CH₃)₂CO can be distunguished by testing with

• Phenyl hydrazine A
• Hydroxylamine B
• Fehling solution C
• Sodium bisulphate D

Which is used for the reduction of aldehydes and ketones

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

Hydrogenation of bezoyl chloride in presence of Pd on BaSO₄gives

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

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 organic compounds exhibits positive Fehling test as well as iodoform test?

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

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

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

Which of the following will have the highest boiling point

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

Chromic acid used to oxidize

• Aldehyde A
• Ketone B
• Both a and b 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

Distillation of calcium salts of acetic acid and formic acids gives acetaldehyde. What compound would be obtained if only calcium salt of acetic acid is distilled

• Formaldehyde A
• Butyraldehyde B
• Propionaldehyde C
• Acetone D

Reductive ozonolysis of benzene produces

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

Condensation of aldeydes withα-hydrogen gives:

• Acetal A
• Ketal B
• Aldol C
• Cannizzaro product 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

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

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

Which reaction yields Bakelite?

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

From which of the following tertiary butyl alcohol is obtained by the action of methyl magnesium iodide?

• HCHO A
• CH₃CHO B
• CH₃COCH₃ C
• CO₂ 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

Which of the following compounds gives a ketone with Grignard's reagent?

• Formaldehyde A
• Ethanenitrile B
• Ethyl alcohol C
• Methyl iodide D

Acetone is oxidized with

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

Chromyl chloride and toluene react to produce

• p-chlorotoluene A
• Benzaldehyde B
• Benzyl chloride C
• Bezoic acid D

Which alcohol may be oxidised to a product which react with 2,4-dinitorphenylhydrazine reagent but not with Fehling's reagent

• Butan-1-ol A
• Butan-2-ol B
• 2-methylpropan-1-ol C
• 2-methylpropan-2-ol D

• 2-chlorobutanal A
• alfa-chlorobutanal B
• 2-chlorobutyraldehyde C
• alfa- chlorobutyraldehyde D

A common industrial solvent is a mixture of propanone; CH₃COCH₃, and pentyl ethanoate CH₃CO₂(CH₂)₄CH₃. Which reagent would have no effect on this solvent

• Na_(s) A
• NaBH₄ B
• NaOH_(aq) C
• 2,4-dinitrophenylhydrazine reagent D

A nucleophilic reagent will readily Attack

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

Reduction of aldehydes with HI and P gives

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