Problem 88 - A Complete Resource Book in Chemistry for JEE Main

Question

When mercury boils with \(\mathrm{H}_{2} \mathrm{SO}_{4}\), then it formed and is liberated. (a) \(\mathrm{Hg}_{2} \mathrm{SO}_{4}, \mathrm{SO}_{2}\) (b) \(\mathrm{HgSO}_{4}, \mathrm{SO}_{2}\) (c) \(\mathrm{HgSO}_{4}, \mathrm{SO}_{3}\) (d) \(\mathrm{HgSO}_{4}, \mathrm{H}_{2}\)

Step-by-Step Solution

Answer

(b) HgSO_4, SO_2 .

Step 1: Understanding the Reaction

When mercury (Hg) reacts with sulfuric acid ( H_2SO_4 ), certain compounds can be formed. This is a classic reaction in chemistry where reactive metals are often oxidized, and sulfur-oxygen compounds are released. The focus here is on determining the correct products of this reaction based on chemical principles.

Step 2: Identify Possible Products

The possible products listed in the options involve the formation of different mercury sulfates (either Hg_2SO_4 or HgSO_4 ) and the release of gaseous compounds like SO_2 , SO_3 , and H_2 . We must determine which is most likely.

Step 3: Apply Principles of Chemical Reactions

In reactions of metals with concentrated sulfuric acid, it is common to form a sulfate of the metal and a gaseous product. Based on known reaction patterns, it's typical for sulfates to form along with sulfur dioxide ( SO_2 ) as the gas, rather than other sulfur or hydrogen gases.

Step 4: Conclusion and Verification

The reaction of mercury with concentrated sulfuric acid typically results in the formation of HgSO_4 and SO_2 . This corresponds to option (b) HgSO_4, SO_2 . Hg_2SO_4 and gases like SO_3 or H_2 are less consistent with typical reaction behavior for this metal and acid combination.

Key Concepts

Mercury Reactions

Mercury, a dense liquid metal at room temperature, exhibits fascinating reactions, especially when exposed to acids. One noteworthy interaction occurs when mercury (Hg) comes into contact with sulfuric acid (H₂SO₄). This type of reaction is characterized by the transfer of electrons, leading to the generation of new compounds.

In the context of mercury reactions with sulfuric acid, mercury acts as a reducing agent. This means that it donates electrons during the reaction. Sulfuric acid, on the other hand, functions as an oxidizer, accepting electrons. As a result, mercury undergoes oxidation, forming mercury sulfate (HgSO₄), reflecting a typical chemical transformation where a metal reacts with an acid.

Reactions like these are significant in understanding basic principles of redox chemistry, where oxidation and reduction processes are deeply intertwined. Redox reactions play a critical role in many chemical synthesis processes and in industrial applications where mercury reactions are applied.

Sulfuric Acid Chemistry

Sulfuric acid is one of the most widely used acids in both laboratories and industry. It's known for its strong acidic nature and high oxidizing potential. Understanding its behavior is crucial to mastering chemistry concepts.

In chemical reactions, sulfuric acid ( H₄) behaves as both an acid and an oxidizer. This dual role allows it to participate in a wide variety of chemical processes. It can donate protons (H⁺), which is a characteristic behavior of acids, and it can also accept electrons from other substances, demonstrating its capacity as an oxidizing agent.

When sulfuric acid comes into contact with metals, especially those which can be oxidized, it frequently leads to the formation of metal sulfate compounds. In this process, the metal gets converted into its sulfate form while sulfur dioxide (SO₂) often gets liberated due to the reduction of sulfurous elements within the acid. This is why sulfuric acid is so effective in converting a wide range of metals into their respective sulfates.

Metal Sulfates Formation

The formation of metal sulfates is a common result when metals react with sulfuric acid. But what makes this process so interesting? Let's delve into it.

Metal sulfates are created when sulfuric acid reacts with a metal, converting it into its sulfate salt. This involves the substitution of the metal into the sulfuric acid, resulting in a sulfate of the metal. The general formula for a metal sulfate product is often represented as MSO₄, where M symbolizes the metal involved in the reaction.

This transformation is critical not only for academic purposes but also for industrial applications. Metal sulfates such as mercury sulfate (HgSO₄) find use in different chemical and manufacturing processes. During the reaction, release of gases like sulfur dioxide (SO₂) is often observed, which is an important aspect of the reaction's chemistry.

Understanding the formation and properties of metal sulfates can provide insights into the broader applications and implications of inorganic chemistry, making it essential knowledge for students and professionals alike.