Which Of The Following Is An Example Of A Decomposition Reaction?A. $ Zn + 2HCl \rightarrow ZnCl_2 + H_2 $B. $ CaCl_2 + Na_2CO_3 \rightarrow CaCO_3 + 2NaCl $C. $ H_2 + Cl_2 \rightarrow 2HCl $D. $ 2NaCl \rightarrow 2Na +

Mar 11, 2025 by ADMIN 220 views

**Decomposition Reactions: Understanding the Basics**

Introduction

Chemical reactions are a fundamental aspect of chemistry, and understanding the different types of reactions is crucial for grasping the subject. One such type of reaction is the decomposition reaction, where a single compound breaks down into two or more simpler substances. In this article, we will explore what decomposition reactions are, provide examples, and discuss the key characteristics of these reactions.

What is a Decomposition Reaction?

A decomposition reaction is a type of chemical reaction where a single compound breaks down into two or more simpler substances. This type of reaction involves the breakdown of a compound into its constituent elements or simpler compounds. Decomposition reactions can be either spontaneous or induced, meaning they can occur on their own or require external energy to initiate.

Examples of Decomposition Reactions

Let's take a look at some examples of decomposition reactions:

Example 1: Thermal Decomposition of Calcium Carbonate

When calcium carbonate (CaCO3) is heated, it decomposes into calcium oxide (CaO) and carbon dioxide (CO2). This reaction is an example of a thermal decomposition reaction.

CaCO3 → CaO + CO2

Example 2: Electrolysis of Water

When an electric current is passed through water, it decomposes into hydrogen gas (H2) and oxygen gas (O2). This reaction is an example of an electrolysis decomposition reaction.

2H2O → 2H2 + O2

Example 3: Photodecomposition of Silver Chloride

When silver chloride (AgCl) is exposed to sunlight, it decomposes into silver (Ag) and chlorine gas (Cl2). This reaction is an example of a photodecomposition reaction.

2AgCl → 2Ag + Cl2

Which of the Following is an Example of a Decomposition Reaction?

Now, let's take a look at the options provided:

A. $ Zn + 2HCl \rightarrow ZnCl_2 + H_2 $ B. $ CaCl_2 + Na_2CO_3 \rightarrow CaCO_3 + 2NaCl $ C. $ H_2 + Cl_2 \rightarrow 2HCl $ D. $ 2NaCl \rightarrow 2Na + Cl_2 $

To determine which of these options is an example of a decomposition reaction, we need to analyze each reaction.

Option A: Zinc and Hydrochloric Acid Reaction

In this reaction, zinc (Zn) reacts with hydrochloric acid (HCl) to form zinc chloride (ZnCl2) and hydrogen gas (H2). This reaction is an example of a single displacement reaction, not a decomposition reaction.

Option B: Calcium Chloride and Sodium Carbonate Reaction

In this reaction, calcium chloride (CaCl2) reacts with sodium carbonate (Na2CO3) to form calcium carbonate (CaCO3) and sodium chloride (NaCl). This reaction is an example of a double displacement reaction, not a decomposition reaction.

Option C: Hydrogen and Chlorine Gas Reaction

In this reaction, hydrogen gas (H2) reacts with chlorine gas (Cl2) to form hydrogen chloride (HCl). This reaction is an example of a combination reaction, not a decomposition reaction.

Option D: Sodium Chloride Decomposition

In this reaction, sodium chloride (NaCl) decomposes into sodium (Na) and chlorine gas (Cl2). This reaction is an example of a decomposition reaction.

Conclusion

In conclusion, a decomposition reaction is a type of chemical reaction where a single compound breaks down into two or more simpler substances. The examples provided demonstrate the different types of decomposition reactions, including thermal, electrolysis, and photodecomposition reactions. By analyzing the options provided, we can determine that option D is the correct answer, as it represents a decomposition reaction.

Key Takeaways

Decomposition reactions involve the breakdown of a compound into its constituent elements or simpler compounds.
Examples of decomposition reactions include thermal, electrolysis, and photodecomposition reactions.
To determine if a reaction is a decomposition reaction, look for the breakdown of a single compound into two or more simpler substances.

Frequently Asked Questions

Q: What is a decomposition reaction?

A decomposition reaction is a type of chemical reaction where a single compound breaks down into two or more simpler substances.

Q: What are some examples of decomposition reactions?

Some examples of decomposition reactions include thermal decomposition of calcium carbonate, electrolysis of water, and photodecomposition of silver chloride.

Q: How do I determine if a reaction is a decomposition reaction?

To determine if a reaction is a decomposition reaction, look for the breakdown of a single compound into two or more simpler substances.

References

Chemistry: An Atoms First Approach by Steven S. Zumdahl
General Chemistry: Principles and Modern Applications by Linus Pauling
Chemistry: The Central Science by Theodore L. Brown
Decomposition Reactions: Q&A =============================

Introduction

In our previous article, we explored the concept of decomposition reactions, including their definition, examples, and key characteristics. In this article, we will delve deeper into the world of decomposition reactions by answering some frequently asked questions.

Q&A

Q: What is the difference between a decomposition reaction and a combination reaction?

A: A decomposition reaction involves the breakdown of a single compound into two or more simpler substances, whereas a combination reaction involves the combination of two or more substances to form a new compound.

Q: Can a decomposition reaction be spontaneous or induced?

A: Yes, a decomposition reaction can be either spontaneous or induced. Spontaneous decomposition reactions occur on their own, while induced decomposition reactions require external energy to initiate.

Q: What are some common examples of decomposition reactions?

A: Some common examples of decomposition reactions include:

Thermal decomposition of calcium carbonate (CaCO3)
Electrolysis of water (H2O)
Photodecomposition of silver chloride (AgCl)
Decomposition of hydrogen peroxide (H2O2)

Q: How do I determine if a reaction is a decomposition reaction?

A: To determine if a reaction is a decomposition reaction, look for the breakdown of a single compound into two or more simpler substances. You can also check if the reaction involves the loss of a molecule or the formation of a new compound.

Q: Can a decomposition reaction be reversible?

A: Yes, a decomposition reaction can be reversible. In some cases, the products of a decomposition reaction can react with each other to form the original compound.

Q: What are some common applications of decomposition reactions?

A: Some common applications of decomposition reactions include:

Production of hydrogen gas (H2) for fuel cells
Production of oxygen gas (O2) for medical and industrial applications
Decomposition of pollutants in the environment
Production of chemicals for various industries

Q: Can a decomposition reaction be used to produce energy?

A: Yes, a decomposition reaction can be used to produce energy. For example, the decomposition of hydrogen peroxide (H2O2) can be used to produce oxygen gas (O2) and energy.

Q: What are some safety precautions to take when working with decomposition reactions?

A: When working with decomposition reactions, it is essential to take safety precautions to avoid accidents and injuries. Some common safety precautions include:

Wearing protective gear, such as gloves and goggles
Working in a well-ventilated area
Avoiding contact with the reaction mixture
Following proper procedures for handling and disposing of chemicals