Question

Describe two reactions in which sulfuric acid acts as an oxidizing agent.

Short answer

Sulfuric acid acts as an oxidizing agent in its reactions with copper and zinc.

Step-by-step solution

Understanding Oxidizing Agents

In a redox reaction, an oxidizing agent is a substance that gains electrons and is reduced in the process. Sulfuric acid can act as an oxidizing agent because it can accept electrons from other substances.

Reaction 1: Sulfuric Acid with Copper

When sulfuric acid reacts with copper, it acts as an oxidizing agent. The chemical reaction is: \[ Cu + 2H_2SO_4 ightarrow CuSO_4 + SO_2 + 2H_2O \]Here, copper (Cu) is oxidized to copper sulfate (CuSO_4), and sulfuric acid is reduced to sulfur dioxide (SO_2).

Reaction 2: Sulfuric Acid with Zinc

In another reaction, sulfuric acid acts as an oxidizing agent when reacting with zinc: \[ Zn + 2H_2SO_4 ightarrow ZnSO_4 + SO_2 + 2H_2O \]In this reaction, zinc (Zn) is oxidized to zinc sulfate (ZnSO_4), and sulfuric acid is reduced to sulfur dioxide (SO_2).

Key concepts

Redox Reaction

In chemistry, a redox reaction is a fundamental process involving two simultaneous changes: reduction and oxidation. These reactions are crucial because they account for many processes in both living organisms and industrial applications. - **Oxidation** is the loss of electrons by a molecule, atom, or ion. - **Reduction** is the gain of electrons. The substance that provides electrons gets oxidized, while the one that receives electrons gets reduced. Understanding redox reactions is key to deciphering how various chemical reactions occur, such as the reactions involving sulfuric acid as an oxidizing agent.

Electron Transfer

In a redox reaction, the transfer of electrons from one substance to another is a primary mechanism. This electron transfer process is what makes redox reactions distinct and essential: - When an atom loses electrons, it undergoes oxidation, leading to an increase in oxidation state. - Conversely, the atom or molecule that gains those electrons undergoes reduction, thereby reducing its oxidation state. Electrons are the "currency" of these reactions, balancing the redox equation. Without the movement of electrons, substances would not undergo the transformations needed to activate or deactivate their chemical properties. This concept is especially pertinent in reactions where sulfuric acid acts as an oxidizing agent, accepting electrons from metals like copper, which in turn are oxidized.

Copper and Sulfuric Acid Reaction

The reaction between copper and sulfuric acid is a classic example illustrating sulfuric acid's role as an oxidizing agent. The balanced chemical reaction is:\[ Cu + 2H_2SO_4 \rightarrow CuSO_4 + SO_2 + 2H_2O \]In this reaction:- Copper (Cu) is oxidized to copper sulfate (CuSO_4) while sulfuric acid (H_2SO_4) gets reduced.- The sulfuric acid accepts electrons from the copper, leading to the formation of sulfur dioxide (SO_2) and water.This process demonstrates the dual role of sulfuric acid as both a supplier of sulfate ions and an agent of oxidation, highlighting its chemical versatility and essential role in various chemical reactions.

Sulfur Dioxide Formation

Sulfur dioxide (SO_2) formation is a key result of the redox reaction involving sulfuric acid, particularly with metals such as copper. It is a direct outcome of sulfuric acid acting as an oxidizing agent. In these reactions, sulfuric acid is reduced, which means it gains electrons, leading to the reduction of sulfate to sulfur dioxide: - As sulfuric acid accepts electrons, the sulfur within it is stripped of oxygen atoms, forming SO_2. - Sulfur dioxide is a colorless gas with a pungent odor, significant in several industrial processes and also as an indicator of atmospheric pollution. Understanding how sulfur dioxide is formed in these reactions demonstrates the interconnectedness of oxidation-reduction processes and their practical applications, from metallurgy to environmental science.