Question

Carbon and hydrogen are detected by heating the compound with which of the following?

(a) Copper (II)oxide

(b) Iron(II)oxide

(c) Iron(III)oxide

(d) Copper(I)oxide

I had been asked this question by my college professor while I was bunking the class.

My question is taken from Qualitative Analysis of Organic Compounds in portion Organic Chemistry – Basic Principles and Technique of Chemistry – Class 11

Answer 1

Right choice is (a) Copper (II)oxide

To explain I would say: Carbon and hydrogen are detected by heating the compound with copper (II) oxide. In this way, the carbon that is present in the compound will be oxidized to carbon dioxide and hydrogen to water. Carbon dioxide is tested by limewater which develops turbidity, and hydrogen is tested with anhydrous copper sulphate, which turns blue.