ECAT Pre Engineering Chemistry Chapter 23 MCQ Test With Answer

Which of the following is hypnotic?

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

Which is used for the reduction of aldehydes and ketones

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

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

Reduction of aldehydes with HI and P gives

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

Aldehydes can be distinguished from ketones by

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

Which is not true about acetophenone?

• Reacts to form 2,4-dintrophenyl hydrazine A
• Reacts with Tollen's reagent to form silver mirror B
• Reacts with I₂/NaOH to form iodoform C
• On oxidation with alkaline KMnO₄followed by hydrolysis gives benzoic acid D

Ketones are prepared by the oxidation of

• Primary alcohol A
• Secondary alcohol B
• Tertiary alcohol C
• None 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

Cannizzaro's reaction in not given by

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

Which compound would undergo nucleophilic addition

• Ethene, C₂H₄ A
• Bromoethane, C₂H₅Br B
• Ethanal, CH₃CHO C
• Ethane, C₂H₆ D

Aldehydes give reactions :

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

Reaction of Grignard's reagent with formaldehyde gives:

• pri-alcohol A
• sec-alcohol B
• ter-alcohol C
• carboxylic D

Dehydration of allcohol gives:

• Alkane A
• Alkene B
• Aldehyde C
• ketone 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

Give IUPAC name fo Acetone

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

The carbon atom of a carbonyl group is

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

• With H₂/Ni CH₃(CH₂)₅CH₂OH A
• With H₂/Ni CH₃(CH₂)₅CH₃ B
• With NaBH₄ CH₃(CH₂)₅CH₂OH C
• With NaBH₄ CH₃(CH₂)₅CHO D

Chromic acid used to oxidize

• Aldehyde A
• Ketone B
• Both a and b C
• None of these D

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

• 
  A
• 
  B
• 
  C
• 
  D

Cannizzaro reaction is not given by

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

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

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

Aledehydes ketones can be prepared form alcohols by their:

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

Aldehydes which do not haveα-hydrogen undergo

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

Ketones are prepared by the oxidation of:

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

When vapours of isopropyl alcohol are passed over heated copper, the major product obtained is

• Propane A
• Propylene B
• Acetaldehyde C
• Acetone 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

Ketones are reduced to

• Primary alcohol A
• Secondary alcohol B
• Tertiary alcohol C
• All of these D

On adding sodium nitroprusside ketones give

• Red A
• Wine red B
• White C
• Orange D