NEET Chemistry - New - Aldehydes, Ketones and Carboxylic Acids

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Question - 1

Predict the correct intermediate and product in the following reaction.
H3C - C ≡ CH \(\xrightarrow [ { H }_{ 2 }O,{ H }_{ 2 }{ SO }_{ 4 } ]{ { HgSO }_{ 4 } } \)
Intermediate ⟶ Product

  • A \(A={ H }_{ 3 }C-\underset { \overset { | }{ { SO }_{ 4 } } }{ \overset { (A) }{ C } } ={ CH }_{ 2 },\) \(B={ H }_{ 3 }C-\underset { \overset { || }{ { O } } }{ \overset { (B) }{ C } } ={ CH }_{ 3 }\)
  • B \(A={ H }_{ 3 }C-\underset { \overset { | }{ { OH } } }{ C } ={ CH }_{ 2 },\) \(B={ H }_{ 2 }C-\underset { \overset { | }{ { { SO }_{ 4 } } } }{ C } ={ CH }_{ 2 }\)
  • C \(A={ H }_{ 3 }C-\underset { \overset { || }{ { O } } }{ C } ={ CH }_{ 3 },\) B = H C - C ≡ CH
  • D \(A={ H }_{ 3 }C-\underset { \overset { || }{ { OH } } }{ C } ={ CH }_{ 3 },\) \(B={ H }_{ 3 }C-\underset { \overset { || }{ { O } } }{ C } ={ CH }_{ 3 }\)

Question - 2

Which of the following reagents would distinguish cis-cyclopenta-1, 2-diol from the trans-isomer?

  • A MnO2
  • B Aluminium isopropoxide
  • C Acetone
  • D Ozone

Question - 3

The correct statement regarding a carbonyl compound with a hydrogen atom on its alphacarbon, is:

  • A a carbonyl compound with a hydrogen atom on its alpha carbon rapidly equilibrates with its corresponding enol and this process is known as carbonylation
  • B a carbonyl compound with a hydrogen atom on its alpha carbon rapidly equilibrates with its corresponding enol and this process is known as keto-enol tautomerism
  • C a carbonyl compound with a hydrogen atom on its alpha-carbon never equilibrates with its corresponding enol.
  • D a carbonyl compound with a hydrogen atom on its alpha-carbon rapidly equilibrates with tis corresponding enol and this process is known as aldehyde-ketone equilibration.

Question - 4

An organic compound X having molecular formula C5H10O yields phenyl hydrazone and gives negative response to the iodoform test and Tollen's test. It produces n-pentane on reduction. X could be:

  • A pentanal
  • B 2-pentanone
  • C 3-pentanone
  • D n-amyl alcohol

Question - 5

Reaction by which benzaldehyde cannot be prepared?

  • A
  • B
  • C
  • D

Question - 6

Clemmensen reduction of a ketone is carried out in the presence of which of the following?

  • A Zn-Hg with HCI
  • B LIAIH6
  • C H2 and Pt as catalyst
  • D Glycol With KOH

Question - 7

A strong base can abstract an α-hydrogen from:

  • A alkene
  • B amine
  • C ketone
  • D alkane

Question - 8

In this reaction CH3CHO + HCN ⟶ CH3CH(OH)CN \(\underrightarrow { H.OH } \) CH3CH(OH)COOH An asymmetric centre is generated. The acid obtained would be:

  • A 50% D + 50% L-isomer
  • B 20% D + 80% L-isomer
  • C D-isomer
  • D L-isomer

Question - 9

Polarisation of electrons in acrolein may be written as:

  • A \(\overset { \delta + }{ { CH }_{ 2 } } =CH-CH=\overset { \delta - }{ O } \)
  • B \(\overset { \delta + }{ { CH }_{ 2 } } =\overset { \delta + }{ CH } -CH=O\)
  • C \(\overset { \delta + }{ { CH }_{ 2 } } =CH-CH=\overset { \delta + }{ O } \)
  • D \(\overset { \delta + }{ { CH }_{ 2 } } =CH-\overset { \delta + }{ CH } =O\)

Question - 10

During reduction of aldehydes with hydrazine and potassium hydroxide, the first is the formation of:

  • A R - CH = NH2
  • B R - C = N
  • C \(R-\underset { \overset { || }{ O } }{ C } -{ NH }_{ 2 }\)
  • D R - CH =NH