Consider This Reaction: N H 4 + + H P O 4 2 − → N H 3 + H 2 P O 4 − NH_4^+ + HPO_4^{2-} \rightarrow NH_3 + H_2PO_4^- N H 4 + + H P O 4 2 − → N H 3 + H 2 P O 4 − Which Is The Bronsted-Lowry Acid?A. N H 4 + NH_4^+ N H 4 + B. H P O 4 2 − HPO_4^{2-} H P O 4 2 − C. H P O 4 2 − HPO_4^{2-} H P O 4 2 − D. H 2 P O 4 − H_2PO_4^- H 2 P O 4 −

Mar 7, 2025 by ADMIN 353 views

**Understanding the Bronsted-Lowry Acid-Base Theory**

In chemistry, the Bronsted-Lowry acid-base theory is a fundamental concept that explains the behavior of acids and bases. This theory, proposed by Johannes Bronsted and Thomas Lowry in the early 20th century, provides a comprehensive framework for understanding acid-base reactions. In this article, we will delve into the Bronsted-Lowry acid-base theory and apply it to a specific reaction to determine the Bronsted-Lowry acid.

What is the Bronsted-Lowry Acid-Base Theory?

The Bronsted-Lowry acid-base theory defines an acid as a molecule that donates a proton (H+ ion) and a base as a molecule that accepts a proton. This theory is based on the idea that acids and bases are not fixed entities, but rather they can exist in different forms depending on the reaction conditions. The Bronsted-Lowry theory also introduces the concept of conjugate acid-base pairs, where a base can be converted into an acid by accepting a proton, and vice versa.

Key Concepts in the Bronsted-Lowry Acid-Base Theory

Acid: A molecule that donates a proton (H+ ion).
Base: A molecule that accepts a proton (H+ ion).
Conjugate acid-base pairs: A base that has accepted a proton becomes a conjugate acid, and an acid that has donated a proton becomes a conjugate base.

Applying the Bronsted-Lowry Acid-Base Theory to the Reaction

Now, let's apply the Bronsted-Lowry acid-base theory to the reaction:

$NH_4^+ + HPO_4^{2-} \rightarrow NH_3 + H_2PO_4^-$

To determine the Bronsted-Lowry acid, we need to identify the molecule that donates a proton (H+ ion) in the reaction.

Step 1: Identify the Molecules Involved in the Reaction

The reaction involves four molecules: $NH_4^+$ , $HPO_4^{2-}$ , $NH_3$ , and $H_2PO_4^-$ . We need to examine each molecule to determine which one donates a proton.

Step 2: Analyze the Reaction to Determine the Bronsted-Lowry Acid

Looking at the reaction, we can see that $NH_4^+$ is the molecule that donates a proton to $HPO_4^{2-}$ , resulting in the formation of $NH_3$ and $H_2PO_4^-$ . This indicates that $NH_4^+$ is the Bronsted-Lowry acid in this reaction.

Conclusion

In conclusion, the Bronsted-Lowry acid-base theory provides a comprehensive framework for understanding acid-base reactions. By applying this theory to the reaction $NH_4^+ + HPO_4^{2-} \rightarrow NH_3 + H_2PO_4^-$ , we have determined that $NH_4^+$ is the Bronsted-Lowry acid.

Answer

The correct answer is:

A. $NH_4^+$

Additional Examples and Applications

The Bronsted-Lowry acid-base theory has numerous applications in chemistry, including:

Acid-base titrations: The theory is used to determine the concentration of acids and bases in solutions.
pH calculations: The theory is used to calculate the pH of solutions.
Buffer solutions: The theory is used to understand the behavior of buffer solutions.

Conclusion

In our previous article, we explored the Bronsted-Lowry acid-base theory and applied it to a specific reaction to determine the Bronsted-Lowry acid. In this article, we will answer some frequently asked questions about the Bronsted-Lowry acid-base theory.

Q: What is the Bronsted-Lowry acid-base theory?

A: The Bronsted-Lowry acid-base theory is a fundamental concept in chemistry that explains the behavior of acids and bases. It defines an acid as a molecule that donates a proton (H+ ion) and a base as a molecule that accepts a proton.

Q: What is the difference between the Bronsted-Lowry acid-base theory and the Arrhenius theory?

A: The Arrhenius theory defines an acid as a molecule that donates a hydrogen ion (H+) in solution and a base as a molecule that donates a hydroxide ion (OH-). The Bronsted-Lowry acid-base theory, on the other hand, defines an acid as a molecule that donates a proton (H+ ion) and a base as a molecule that accepts a proton.

Q: What is a conjugate acid-base pair?

A: A conjugate acid-base pair is a pair of molecules that differ by one proton (H+ ion). A base can be converted into an acid by accepting a proton, and vice versa.

Q: How do you determine the Bronsted-Lowry acid in a reaction?

A: To determine the Bronsted-Lowry acid in a reaction, you need to identify the molecule that donates a proton (H+ ion). This can be done by examining the reaction and identifying the molecule that loses a proton.

Q: What is the relationship between pH and the Bronsted-Lowry acid-base theory?

A: The pH of a solution is a measure of its acidity or basicity. The Bronsted-Lowry acid-base theory provides a framework for understanding the behavior of acids and bases in solution, which is essential for calculating pH.

Q: What are some common applications of the Bronsted-Lowry acid-base theory?

A: The Bronsted-Lowry acid-base theory has numerous applications in chemistry, including:

Acid-base titrations: The theory is used to determine the concentration of acids and bases in solutions.
pH calculations: The theory is used to calculate the pH of solutions.
Buffer solutions: The theory is used to understand the behavior of buffer solutions.

Q: What are some common mistakes to avoid when applying the Bronsted-Lowry acid-base theory?

A: Some common mistakes to avoid when applying the Bronsted-Lowry acid-base theory include:

Failing to identify the Bronsted-Lowry acid: Make sure to identify the molecule that donates a proton (H+ ion) in the reaction.
Failing to consider the conjugate acid-base pair: Make sure to consider the conjugate acid-base pair when applying the theory.
Failing to calculate the pH correctly: Make sure to calculate the pH correctly using the Bronsted-Lowry acid-base theory.

Conclusion

In this article, we have answered some frequently asked questions about the Bronsted-Lowry acid-base theory. We hope that this article has provided a better understanding of the theory and its applications. If you have any further questions, please don't hesitate to ask.

Additional Resources

For further reading on the Bronsted-Lowry acid-base theory, we recommend the following resources:

Textbooks: "Chemistry: The Central Science" by Theodore L. Brown, H. Eugene LeMay, and Bruce E. Bursten
Online resources: Khan Academy, Chemistry LibreTexts
Research articles: Search for peer-reviewed articles on the Bronsted-Lowry acid-base theory in academic databases such as Google Scholar or Web of Science.