Consider The Reaction Below:${ H_2PO_4^{-} + H_2O \rightarrow H_3O^{+} + HPO_4^{2-} }$Which Of The Following Is A Base-conjugate Acid Pair?A. { H_2O $}$ And { H_3O^{+} $}$ B. { H_2O $}$ And [$

by ADMIN 195 views

Introduction

In chemistry, acid-base conjugate pairs play a crucial role in understanding the behavior of acids and bases. A conjugate acid is formed when an acid donates a proton (H+), while a conjugate base is formed when a base accepts a proton. In this article, we will explore the concept of acid-base conjugate pairs and identify the correct pair from the given reaction.

What are Acid-Base Conjugate Pairs?

Acid-base conjugate pairs are pairs of substances that differ by one proton (H+). When an acid donates a proton, it forms a conjugate base, and when a base accepts a proton, it forms a conjugate acid. This process is known as acid-base dissociation.

The Reaction

Consider the reaction below:

H2PO4−+H2O→H3O++HPO42−{ H_2PO_4^{-} + H_2O \rightarrow H_3O^{+} + HPO_4^{2-} }

In this reaction, the phosphate ion (H2PO4-) donates a proton to water (H2O), forming hydronium ion (H3O+) and hydrogen phosphate ion (HPO42-).

Identifying the Conjugate Acid-Base Pair

To identify the conjugate acid-base pair, we need to look for the substance that has gained or lost a proton. In this reaction, the phosphate ion (H2PO4-) has lost a proton to form the hydrogen phosphate ion (HPO42-). Therefore, the phosphate ion (H2PO4-) and the hydrogen phosphate ion (HPO42-) are a conjugate acid-base pair.

Analyzing the Options

Now, let's analyze the options given:

A. H2O{ H_2O } and H3O+{ H_3O^{+} }

In this option, water (H2O) and hydronium ion (H3O+) are not a conjugate acid-base pair. Water is a neutral substance, and hydronium ion is a strong acid. They do not differ by one proton.

B. H2O{ H_2O } and HPO42−{ HPO_4^{2-} }

In this option, water (H2O) and hydrogen phosphate ion (HPO42-) are not a conjugate acid-base pair. Water is a neutral substance, and hydrogen phosphate ion is a conjugate base. They do not differ by one proton.

C. H2PO4−{ H_2PO_4^{-} } and HPO42−{ HPO_4^{2-} }

In this option, phosphate ion (H2PO4-) and hydrogen phosphate ion (HPO42-) are a conjugate acid-base pair. The phosphate ion has lost a proton to form the hydrogen phosphate ion.

Conclusion

In conclusion, the correct conjugate acid-base pair from the given reaction is the phosphate ion (H2PO4-) and the hydrogen phosphate ion (HPO42-). This pair differs by one proton, making them a conjugate acid-base pair.

Key Takeaways

  • Acid-base conjugate pairs are pairs of substances that differ by one proton.
  • A conjugate acid is formed when an acid donates a proton, while a conjugate base is formed when a base accepts a proton.
  • The phosphate ion (H2PO4-) and the hydrogen phosphate ion (HPO42-) are a conjugate acid-base pair.

Frequently Asked Questions

Q: What is a conjugate acid-base pair?

A: A conjugate acid-base pair is a pair of substances that differ by one proton.

Q: How are conjugate acid-base pairs formed?

A: Conjugate acid-base pairs are formed when an acid donates a proton to form a conjugate base, or when a base accepts a proton to form a conjugate acid.

Q: What is the difference between a conjugate acid and a conjugate base?

A: A conjugate acid is formed when an acid donates a proton, while a conjugate base is formed when a base accepts a proton.

Q: What is the significance of acid-base conjugate pairs in chemistry?

A: Acid-base conjugate pairs play a crucial role in understanding the behavior of acids and bases in chemical reactions.

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

Glossary

  • Acid: A substance that donates a proton (H+).
  • Base: A substance that accepts a proton (H+).
  • Conjugate acid: A substance formed when an acid donates a proton.
  • Conjugate base: A substance formed when a base accepts a proton.
  • Proton: A positively charged particle (H+).

Additional Resources

  • Khan Academy: Acid-Base Chemistry
  • Crash Course: Chemistry - Acid-Base Chemistry
  • Chemistry LibreTexts: Acid-Base Chemistry
    Acid-Base Conjugate Pairs: Frequently Asked Questions =====================================================

Introduction

Acid-base conjugate pairs are a fundamental concept in chemistry, and understanding them is crucial for grasping the behavior of acids and bases in chemical reactions. In this article, we will address some of the most frequently asked questions about acid-base conjugate pairs.

Q: What is a conjugate acid-base pair?

A: A conjugate acid-base pair is a pair of substances that differ by one proton (H+). When an acid donates a proton, it forms a conjugate base, and when a base accepts a proton, it forms a conjugate acid.

Q: How are conjugate acid-base pairs formed?

A: Conjugate acid-base pairs are formed when an acid donates a proton to form a conjugate base, or when a base accepts a proton to form a conjugate acid. This process is known as acid-base dissociation.

Q: What is the difference between a conjugate acid and a conjugate base?

A: A conjugate acid is formed when an acid donates a proton, while a conjugate base is formed when a base accepts a proton. The conjugate acid is the substance that has gained a proton, while the conjugate base is the substance that has lost a proton.

Q: What is the significance of acid-base conjugate pairs in chemistry?

A: Acid-base conjugate pairs play a crucial role in understanding the behavior of acids and bases in chemical reactions. They help us predict the direction of acid-base reactions and the strength of acids and bases.

Q: Can a substance be both an acid and a base?

A: Yes, a substance can be both an acid and a base, depending on the conditions. This is known as amphoteric behavior. For example, water (H2O) can act as both an acid and a base.

Q: What is the pH of a solution containing a conjugate acid-base pair?

A: The pH of a solution containing a conjugate acid-base pair depends on the concentration of the conjugate acid and the conjugate base. If the concentration of the conjugate acid is higher, the pH will be lower, and if the concentration of the conjugate base is higher, the pH will be higher.

Q: Can a conjugate acid-base pair be a strong acid or a strong base?

A: No, a conjugate acid-base pair cannot be a strong acid or a strong base. A strong acid or a strong base is a substance that completely dissociates in water, while a conjugate acid-base pair is a pair of substances that differ by one proton.

Q: How do I determine if a substance is a conjugate acid or a conjugate base?

A: To determine if a substance is a conjugate acid or a conjugate base, you need to look at the reaction and see if the substance has gained or lost a proton. If the substance has gained a proton, it is a conjugate acid, and if it has lost a proton, it is a conjugate base.

Q: Can a conjugate acid-base pair be a buffer solution?

A: Yes, a conjugate acid-base pair can be a buffer solution. A buffer solution is a solution that resists changes in pH when an acid or a base is added. A conjugate acid-base pair can act as a buffer solution by neutralizing excess acid or base.

Conclusion

In conclusion, acid-base conjugate pairs are a fundamental concept in chemistry, and understanding them is crucial for grasping the behavior of acids and bases in chemical reactions. By answering these frequently asked questions, we hope to have provided a better understanding of acid-base conjugate pairs and their significance in chemistry.

Additional Resources

  • Khan Academy: Acid-Base Chemistry
  • Crash Course: Chemistry - Acid-Base Chemistry
  • Chemistry LibreTexts: Acid-Base Chemistry

Glossary

  • Acid: A substance that donates a proton (H+).
  • Base: A substance that accepts a proton (H+).
  • Conjugate acid: A substance formed when an acid donates a proton.
  • Conjugate base: A substance formed when a base accepts a proton.
  • Proton: A positively charged particle (H+).
  • pH: A measure of the concentration of hydrogen ions in a solution.
  • Buffer solution: A solution that resists changes in pH when an acid or a base is added.

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