Question 1

What is the formula of the pale yellow solid formed when propanone reacts with iodine in the presence of sodium hydroxide?

  A  

NaI

  B  

CH3COCH2I

  C  

CH3I

  D  

CHI3


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Question 2

Which compound reacts with 2,4-dinitrophenylhydrazine reagent but does not react with Tollens’ reagent?

  A  

CH3COCO2H

  B  

CH3CH(OH)CHO

  C  

CH3COCHO

  D  

CH3CH(OH)CH3

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Question 3

Structural isomerism and stereoisomerism should be considered when answering this question.

The molecular formula of compound X is C5H12O.

Compound X:

● reacts with alkaline aqueous iodine

● can be dehydrated to form two alkenes only.

What could be the identity of compound X?

  A  

CH3CH2CH(CH3)CH2OH

  B  

CH3CH2CH(OH)CH2CH3

  C  

(CH3)2CHCH(OH)CH3


  D  

CH3CH2CH2CH(OH)CH3

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Question 4

Which compound gives a positive test with alkaline aqueous iodine and does not show optical isomerism? 

  A  

CH3COCH2CH2OH

  B  

CH3CH2CH(OH)CHO

  C  

CH3COCH(OH)CH3

  D  

(CH3)2C(OH)CHO

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Question 5

Compound X, CH3CH(OH)CH(CHO)CH3, is heated under reflux with an excess of acidified K2Cr2O7 to form compound Y.

Both X and Y are separately warmed with Fehling’s solution and the observations noted.

What are the observations?

  A  

both X and Y give a red precipitate

  B  

only X gives a red precipitate

  C  

only Y gives a red precipitate

  D  

neither X nor Y gives a red precipitate

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Question 6

Compound X produces a carboxylic acid when heated under reflux with acidified potassium dichromate(VI). Compound X does not react with sodium metal.

What could be the identity of compound X?

  A  

propanal

  B  

propanone

  C  

propan-1-ol


  D  

propan-2-ol

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Question 7

Alcohol Y gives product Z after mild oxidation. Z gives a positive result with Tollens’ reagent and with 2,4-dinitrophenylhydrazine reagent.

What could be the identity of alcohol Y?

  A  

butan-1-ol

  B  

butan-2-ol


  C  

butan-2,3-diol


  D  

2-methylbutan-2-ol

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Question 8

Which reagent cannot be used to distinguish between ethanal and propanone?

  A  

acidified sodium dichromate(VI) solution

  B  

alkaline aqueous iodine


  C  

cold acidified potassium manganate(VII) solution


  D  

Fehling’s reagent

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Question 9

A compound, Q, gives an orange precipitate with 2,4-dinitrophenylhydrazine.

Compound Q is resistant to oxidation.

On reduction, Q gives a product made up of a pair of optical isomers.

Which of the following compounds could be compound Q?

  A  

CH3CH2CH2COCH3


  B  

CH3CH=CHCH(OH)CH3


  C  

CH3CH2CH2CH2CHO

  D  

CH3CH2COCH2CH3


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