Practicing Success

Target Exam

CUET

Subject

Chemistry

Chapter

Organic: Aldehydes, Ketones and Carboxylic Acids

Question:

Case: Read the passage and answer the following questions

Aldehydes and ketones are generally prepared by oxidation of primary and secondary alcohols. Dehydrogenation of alcohols gives aldehydes and ketones. Ozonolysis alkenes give aldehydes ketones or a mixture of both depending on the substitution pattern of the alkene. Aldehydes are prepared from acyl chloride, nitrile, esters and even from hydrocarbons by different kinds of oxidation. Ketones are prepared from benzene or its derivatives through Friedel-Crafts acylation reaction. Carboxylic acids are prepared from aldehydes and ketones on oxidation. Nitriles are hydrolysed to amides and then to carboxylic acids. It is even prepared using Grignard’s reagent.

Which of the following metal is used in dehydrogenation of alcohols to give aldehydes or ketones?

Options:

Silver

Copper

Both of the above

None of these

Correct Answer:

Both of the above

Explanation:

Dehydrogenation of alcohols is suitable for volatile alcohols and is of industrial application. In this method alcohol vapours are passed over heavy metal catalysts (Ag or Cu).