Problem 14 - 43 Years JEE ADVANCED (1978-2020) + JEE MAIN Chapterwise & Topicwise Solved Papers Chemistry

Question

Hydrolysis of one mole of peroxodisulphuric acid produces (a) two moles of sulphuric acid [1996 - 1 Mark] (b) two moles of peroxomonosulphuric acid (c) one mole of sulphuric acid and one mole of peroxomonosulphuric acid (d) one mole of sulphuric acid, one mole of peroxomonosulphuric acid and one mole of hydrogen peroxide.

Step-by-Step Solution

Answer

The correct answer is (a) two moles of sulphuric acid.

Step 1: Understand the Chemical Reaction

The hydrolysis of peroxodisulphuric acid (H2S2O8) involves the reaction of peroxodisulphuric acid with water (H2O). In this reaction, the bonds in peroxodisulphuric acid are broken and new substances are formed.

Step 2: Write the Balanced Chemical Equation

The balanced equation for the hydrolysis of peroxodisulphuric acid is: \[ H_2S_2O_8 + 2H_2O \rightarrow 2H_2SO_4 + H_2O_2 \]In this equation, one mole of H2S2O8 reacts with two moles of water to produce two moles of sulfuric acid (H2SO4) and one mole of hydrogen peroxide (H2O2).

Step 3: Analyze the Products

From the balanced equation, we see the products formed: two moles of sulfuric acid (H2SO4) and one mole of hydrogen peroxide (H2O2). No peroxomonosulphuric acid (H2SO5) is formed in this reaction.

Step 4: Compare with Given Options

Compare the products from the reaction with the given options: - Option (a) suggests two moles of sulfuric acid, which matches part of the products. - Option (d) suggests one mole of sulfuric acid, one mole of peroxomonosulphuric acid, and one mole of hydrogen peroxide. This is incorrect as per the balanced equation. - Option (c) suggests one mole of sulfuric acid and one mole of peroxomonosulfuric acid, which does not match our reaction. The accurate representation from the given options is option (a).

Step 5: Conclude the Result

Based on the balanced chemical equation and analysis, the hydrolysis of one mole of peroxodisulphuric acid produces two moles of sulfuric acid, making the correct answer option (a).

Key Concepts

Hydrolysis

Hydrolysis is a chemical reaction that involves the breaking down of a compound due to a reaction with water. In the context of our exercise, hydrolysis refers to the interaction between peroxodisulphuric acid (H\(_2\)S\(_2\)O\(_8\)) and water. During this process, the complex molecule of peroxodisulphuric acid is broken down when water molecules intervene, leading to the formation of new products such as sulfuric acid and hydrogen peroxide.
Understanding hydrolysis is crucial as it's a common process in various chemical reactions. It not only helps to comprehend specific reactions in organic and inorganic chemistry but also has practical applications in areas such as digestion, where large molecules are broken down into absorbable units.
In our specific reaction of hydrolysis, the critical aspect is how water molecules break the strong bonds within the peroxodisulphuric acid, leading to the formation of multiple products without any formation of peroxomonosulphuric acid.

Peroxodisulphuric Acid

Peroxodisulphuric acid, with the chemical formula H\(_2\)S\(_2\)O\(_8\), is a strong oxidizing agent. It's also known as persulfuric acid and is characterized by the presence of a peroxide bond, which is less common in sulfuric acid forms. This compound is prone to decomposition, especially in the presence of water, which demonstrates its reactive nature.
In industrial and laboratory settings, peroxodisulphuric acid is often used for its oxidative properties. Its hydrolysis leads to the production of sulfuric acid and hydrogen peroxide, both valuable in various chemical processes. For instance, sulfuric acid is widely used in the production of fertilizers, while hydrogen peroxide serves as a bleaching agent and disinfectant.
Despite its benefits, handling peroxodisulphuric acid requires caution due to its strong oxidizing ability, which can lead to explosive reactions under certain conditions.

Sulfuric Acid

Sulfuric acid, represented by the formula H\(_2\)SO\(_4\), is one of the most produced and widely used chemicals globally. It is a dense, colorless, and oily liquid known for being a strong acid and excellent dehydrating agent. In the given hydrolysis reaction, sulfuric acid is one of the two primary products formed.
Its widespread applications include the manufacturing of fertilizers, in petroleum refining, mineral processing, and chemical synthesis. The formation of sulfuric acid through hydrolysis highlights its chemical viability and importance in diverse industries.
In educational settings, understanding the formation and properties of sulfuric acid helps students grasp the practical aspects and magnitude of chemical reactions. The ability to produce sulfuric acid from other compounds showcases the versatility of chemical transformations in real-world applications.

Balanced Chemical Equation

A balanced chemical equation is essential for accurately representing a chemical reaction. It ensures that the same number of each type of atom appears on both the reactant and product sides of the equation, complying with the law of conservation of mass.
In our exercise, the equation for the hydrolysis of peroxodisulphuric acid is: \[ H_2S_2O_8 + 2H_2O \rightarrow 2H_2SO_4 + H_2O_2 \] This equation demonstrates that one molecule of peroxodisulphuric acid reacts with two molecules of water to produce two molecules of sulfuric acid and one molecule of hydrogen peroxide. Each element is equally distributed on both sides of the equation, confirming its balance.
Balancing equations is a fundamental skill in chemistry, crucial for predicting the outcomes of reactions and ensuring proper proportions of reactants. It also forms the basis for stoichiometric calculations, which further enhance the understanding of quantitative aspects of chemistry.