Question

Which of the following is not a process of preparation of hydrogen peroxide? (a) Auto-oxidation of 2 -ethylanthraquinol. (b) By passing oxygen through boiling water. (c) By oxidation of isopropyl alcohol. (d) By reaction of barium peroxide with dil. \(\mathrm{H}_{2} \mathrm{SO}_{4}\)

Short answer

Option (b) By passing oxygen through boiling water is not a process of preparation of hydrogen peroxide.

Step-by-step solution

Understand hydrogen peroxide preparation

Consider the common industrial and laboratory methods for preparing hydrogen peroxide, involving various chemical reactions.

Evaluate each given option

Assess each of the given methods to evaluate if it is a recognized process for the preparation of hydrogen peroxide.

Identify the incorrect process

Compare the options with known preparation methods for hydrogen peroxide. (a) involves the anthraquinone process which is a standard method for large scale production; (c) involves the oxidation of a secondary alcohol, which can yield hydrogen peroxide; (d) involves a classic laboratory method of using barium peroxide. (b) passing oxygen through boiling water does not produce hydrogen peroxide, instead it simply creates saturated oxygen water.

Key concepts

Anthraquinone Process

Hydrogen peroxide is a versatile chemical used in various industrial applications, ranging from bleach to antiseptics. One of the most significant and commonly used methods for producing hydrogen peroxide on an industrial scale is the anthraquinone process. This sophisticated method involves a cycle where an anthraquinone derivative gets reduced to the corresponding anthrahydroquinone, usually by hydrogenation. The anthrahydroquinone then undergoes autoxidation in the presence of air, where it is converted back to the anthraquinone and hydrogen peroxide is formed.

This cyclic process allows for the continuous production of hydrogen peroxide, and since it's a closed system, it minimizes the degradation of the reactants. A key advantage of the anthraquinone process is its ability to produce a highly concentrated form of hydrogen peroxide, which is ideal for commercial distribution and use in various industries.

Oxidation of Isopropyl Alcohol

The oxidation of isopropyl alcohol (IPA) represents another method for the preparation of hydrogen peroxide, albeit less commonly used than the anthraquinone process. During the reaction, isopropyl alcohol undergoes oxidation, typically in the presence of a catalyst like palladium on carbon, which facilitates the removal of hydrogen atoms to create water and hydrogen peroxide.

The process begins with the isopropyl alcohol reacting with molecular oxygen, leading to the creation of acetone and hydrogen peroxide as primary products. The reaction equation can be written as:\[2\,(CH_3)_2CHOH + O_2 \rightarrow 2\,(CH_3)_2CO + H_2O_2\].While this method can produce hydrogen peroxide, it's typically not as efficient as others for large-scale production, but it does illustrate the versatility of hydrogen peroxide synthesis through alcohol oxidation.

Barium Peroxide and Sulfuric Acid Reaction

In the laboratory, hydrogen peroxide can be obtained through the reaction between barium peroxide \((\text{BaO}_2)\) and dilute sulfuric acid \((\text{H}_2\text{SO}_4)\). This exothermic reaction produces barium sulfate, water, and hydrogen peroxide. The barium sulfate precipitates out of the mixture due to its insolubility, which allows for the collection of the soluble hydrogen peroxide from the aqueous solution.

The chemical equation for the reaction is:\[BaO_2 + H_2SO_4 \rightarrow BaSO_4(s) + H_2O_2(aq)\].This process is known for its simplicity and convenience for obtaining relatively small quantities of pure hydrogen peroxide. However, it's not economically viable for mass production due to the limited availability of barium peroxide and the need for careful handling of the reagents and products.