Question

On industrial scale ${H_2}{O_2}$ is prepared by autoxidation of:
A. 2-ethylanthraquinol
B. 2-ethylanthraquinone
C. 1-ethylanthraquinol
D. 1-ethyl anthraquinone

Answer 1

Hint: Try to recall that on an industrial scale ${H_2}{O_2}$ is prepared from an organic compound which is a derivative of anthraquinone and also, it is a pale yellow solid. Now, by using this you can easily find the correct option from the given options.

Complete step by step solution:
It is known to you that commercially ${H_2}{O_2}$ is prepared by autoxidation of an organic compound which is a derivative of anthraquinone.
The organic compound which is a derivative of anthraquinone is 2-ethylanthraquinol.
Hydrogen peroxide is prepared by autoxidation of 2-ethylanthraquinol. It involves oxidation of 2-ethylanthraquinol. The reaction is:

2-ethylanthraquinol is prepared by the reduction of 2-ethylanthraquinone by ${H_2}$ in the presence of palladium.

Therefore, from above we can easily conclude that option A is the correct option to the given question.

Additional information:
Preparation of ${H_2}{O_2}$ by autoxidation of 2-ethylanthraquinol:
First, air is passed through a mixture of 2-ethylanthraquinol mixture in cyclohexane and benzene.
It yields 2-ethylanthraquinone and hydrogen peroxide.
The product, 2-ethylanthraquinone is then reduced. For this, hydrogen under a pressure of 1-3 atmospheres at 4 degree Celsius is passed over 2-ethylanthraquinone in the presence of a Pd catalyst.
This gives back the reactant - 2-ethylanthraquinol.
The ${H_2}{O_2}$ is extracted with water and the solution of required concentration is obtained.

Note: It should be remembered to you that in the autoxidation of 2-ethylanthraquinol, only atmospheric oxygen and hydrogen are used which are inexpensive. Hence, this method is widely used for the preparation of hydrogen peroxide as it is quite cheap.