Oxidation of Alcohols

Which is a secondary alcohol?

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Which alcohol cannot be oxidized by a warm acidified solution of potassium dichromate(VI)?

• 2-methylpropan-1-ol

• propan-1-ol

• butan-2-ol

• 2-methylpropan-2-ol

What organic product will be formed when pentan-2-ol is oxidized by an acidified solution of potassium dichromate(VI).

• pentanal

• pentan-3-one

• pentan-2-one

• pentanoic acid

Ethanol can be oxidized first to ethanal and then to ethanoic acid when it is heated under reflux with an acidified solution of potassium dichromate(VI). What method can be used to obtain ethanal from this reaction before it reacts further to form ethanoic acid?

• Filter off the ethanal as soon as it is formed in the mixture.

• Add sodium hydroxide to neutralize any acid that is formed.

• Carry out the reaction at room temperature.

• Distil the ethanal off from the reaction mixture as soon as it forms.

What colour change will be observed when an acidified solution of potassium dichromate(VI) is added to an excess of a secondary alcohol and the mixture is warmed?

• from green to orange

• from pink to colourless

• from orange to green

• from colourless to pink

Which can undergo oxidation and still retain the same number of carbon atoms in the longest chain?

I. primary alcohols

II. aldehydes

III. secondary alcohols

• I and II only

• I, II and III

• I and III only

• II and III only