Question

In an atmosphere polluted with industrial smog, \(\mathrm{Cu}\) corrodes to a basic sulfate, \(\mathrm{Cu}_{2}(\mathrm{OH})_{2} \mathrm{SO}_{4} .\) Propose a series of chemical reactions to describe this corrosion.

Short answer

The series of reactions depicting the corrosion of copper in a polluted atmosphere can be summed up in three steps - reaction with oxygen to form copper oxide, reaction with water to form copper hydroxide, and reaction with sulfur dioxide to form copper sulfate.

Step-by-step solution

Reaction with Oxygen

The first step in the process of corrosion is usually the reaction of the metal with atmospheric oxygen to form an oxide. In the case of copper, this reaction forms copper (II) oxide (CuO): \[ 2 Cu(s) + O_{2}(g) \rightarrow 2 CuO(s) \] In sulfurous smog, this process can be accelerated by the presence of sulfur dioxide (SO2).

Reaction with Water

The second step in the process involves the reaction of the newly formed copper oxide with moisture in the air to form copper hydroxide. Here is the equation for this reaction: \[ CuO(s) + H_{2}O(l) \rightarrow Cu(OH)_2(s) \]

Reaction with Sulfur Dioxide

In the case of the smog-polluted atmosphere mentioned, sulfur dioxide (SO2) reacts with the copper hydroxide formed in step 2, which results in the formation of copper sulfate: \[ Cu(OH)_2(s) + SO_{2}(g) \rightarrow Cu_{2}(OH)_{2}SO_{4}(s) \]

Key concepts

Chemical Reactions

Chemical reactions are processes where substances, called reactants, change into new substances, known as products. These reactions alter the structure of atoms and molecules, leading to the formation or breaking of chemical bonds. In the context of copper corrosion, the reactions result in the transformation of copper into other compounds when exposed to environmental factors.
One can think of a chemical reaction as a series of step-by-step processes. Each step involves specific interactions between atoms, often involving oxygen or other gases like sulfur dioxide. These gases play significant roles in altering metals such as copper and can speed up the corrosion process in polluted atmospheres.
Understanding these interactions helps in anticipating the outcome of chemical reactions. It aids in crafting solutions to industrial problems like corrosion which can lead to significant damage if left unmanaged.

Industrial Smog

Industrial smog is a type of air pollution that results primarily from industrial processes. It is often composed of a mixture of various pollutants, including sulfur dioxide (SO extsubscript{2}) and particulates emitted from burning fossil fuels.
This smog is a significant environmental concern as it can react with metals, such as copper, leading to their corrosion. The pollutants present in industrial smog accelerate chemical reactions, due to the more reactive environment they create.
Industrial smog not only impacts the environment but also human health. It can lead to respiratory issues and other health concerns. Learning about its chemical compositions helps in understanding its effects and finding ways to mitigate its impact.

Sulfur Dioxide

Sulfur dioxide (SO extsubscript{2}) is a colorless gas with a sharp smell, commonly released from industrial processes, especially those that involve burning fossil fuels. It is a significant contributor to environmental issues like acid rain and is also a primary component of industrial smog.
In terms of chemical reactions, sulfur dioxide readily reacts with other substances. Its presence in the atmosphere can enhance the corrosion of metals by forming more corrosive compounds, such as acidic solutions when combined with moisture. In the context of copper corrosion, SO extsubscript{2} reacts with copper hydroxide leading to the formation of copper sulfate, a more stable compound in the polluted environment.

• Reacts with copper and oxygen to form corrosive compounds.
• Causes environmental harm such as acid rain.
• Commonly found in industrial emissions.

Understanding how sulfur dioxide interacts with other elements helps to frame the broader narrative around industrial pollution and its effects on materials.

Copper Oxide

Copper oxide is a compound formed when copper reacts with oxygen. There are two main types of copper oxide: copper (I) oxide (Cu extsubscript{2}O) and copper (II) oxide (CuO). In corrosive environments, like those polluted with industrial smog, copper (II) oxide is more frequently encountered.
The formation of copper oxide is a crucial first step in the process of copper corrosion, especially when sulfur dioxide is present. It interacts with water to form copper hydroxide, which further reacts with sulfur dioxide to produce a more complex compound, such as copper sulfate.
Copper oxide has various applications beyond corrosion. In its different forms, it's used in batteries, pigments, and even as a catalyst in chemical reactions. Its properties and reactivity under different environmental conditions make it an interesting and multifaceted compound in both industrial and academic studies.