Sulfurous Acid and Hydrogen Sulfite Ion

Oct 13, 2025 by wbrum.org 101 views

Conjugate acid-base pairs are a fundamental concept in chemistry, particularly in the study of acid-base chemistry. These pairs are formed when an acid donates a proton (H+ ion) to a base, resulting in the formation of a new acid and a new base. In this article, we will explore the concept of conjugate acid-base pairs and identify which of the given options is NOT a conjugate acid-base pair.

What are Conjugate Acid-Base Pairs?

Conjugate acid-base pairs are pairs of substances that differ by one proton (H+ ion). When an acid donates a proton to a base, the acid becomes a new base, and the base becomes a new acid. This process is known as acid-base reaction or proton transfer reaction. The acid that donates a proton is called the conjugate acid, and the base that accepts a proton is called the conjugate base.

Examples of Conjugate Acid-Base Pairs

Water and Hydroxide Ion: H2O (water) is a weak acid that donates a proton to form OH- (hydroxide ion), which is a strong base. This is an example of a conjugate acid-base pair.
Ammonia and Ammonium Ion: NH3 (ammonia) is a weak base that accepts a proton to form NH4+ (ammonium ion), which is a weak acid. This is another example of a conjugate acid-base pair.
Sulfurous Acid and Hydrogen Sulfite Ion: H2SO3 (sulfurous acid) is a weak acid that donates a proton to form HSO3- (hydrogen sulfite ion), which is a weak base. This is an example of a conjugate acid-base pair.

Analyzing the Given Options

Now, let's analyze the given options to determine which one is NOT a conjugate acid-base pair.

Option A: $H_3O^+ / OH^- $

Analysis: $H_3O^+$ (hydronium ion) is a strong acid that donates a proton to form $OH^-$ (hydroxide ion), which is a strong base. This is an example of a conjugate acid-base pair.

Option B: $NH_4^+ / NH_3$

Analysis: $NH_4^+$ (ammonium ion) is a weak acid that donates a proton to form $NH_3$ (ammonia), which is a weak base. This is an example of a conjugate acid-base pair.

Option C: $H_2SO_3 / HSO_3^- $

Analysis: $H_2SO_3$ (sulfurous acid) is a weak acid that donates a proton to form $HSO_3^-$ (hydrogen sulfite ion), which is a weak base. This is an example of a conjugate acid-base pair.

Option D: $C_2H_3O_2^- / HC_2H_3O_2 $

Analysis: $C_2H_3O_2^-$ (acetate ion) is a conjugate base of a weak acid, $HC_2H_3O_2$ (acetic acid). However, $C_2H_3O_2^-$ is not a conjugate acid of $HC_2H_3O_2$ . Instead, it is the conjugate base of $HC_2H_3O_2$ . Therefore, this option is NOT a conjugate acid-base pair.

Conclusion

In conclusion, the correct answer is D. $C_2H_3O_2^- / HC_2H_3O_2$ . This option is NOT a conjugate acid-base pair because $C_2H_3O_2^-$ is the conjugate base of $HC_2H_3O_2$ , not the conjugate acid.

Key Takeaways

Conjugate acid-base pairs are pairs of substances that differ by one proton (H+ ion).
Acid-base reactions involve the transfer of a proton from an acid to a base.
Conjugate acid-base pairs are essential in understanding acid-base chemistry.

References

Atkins, P. W., & De Paula, J. (2010). Physical chemistry. Oxford University Press.
Chang, R. (2010). Chemistry: The Central Science. McGraw-Hill.
Petrucci, R. H., Harwood, W. S., & Herring, F. G. (2006). General chemistry: Principles and modern applications. Pearson Prentice Hall.
Frequently Asked Questions (FAQs) on Conjugate Acid-Base Pairs ====================================================================

In this article, we will address some of the most frequently asked questions on conjugate acid-base pairs.

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

A: An acid is a substance that donates a proton (H+ ion), while a base is a substance that accepts a proton. In other words, an acid is a proton donor, and a base is a proton acceptor.

Q: What is the relationship between an acid and its conjugate base?

A: An acid and its conjugate base differ by one proton (H+ ion). When an acid donates a proton, it becomes a new base, and the base becomes a new acid.

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

A: A base and its conjugate acid differ by one proton (H+ ion). When a base accepts a proton, it becomes a new acid, and the acid becomes a new base.

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

A: Yes, a conjugate acid-base pair can be a strong acid and a strong base. For example, H+ (hydronium ion) and OH- (hydroxide ion) are a conjugate acid-base pair, where H+ is a strong acid and OH- is a strong base.

Q: Can a conjugate acid-base pair be a weak acid and a weak base?

A: Yes, a conjugate acid-base pair can be a weak acid and a weak base. For example, NH3 (ammonia) and NH4+ (ammonium ion) are a conjugate acid-base pair, where NH3 is a weak base and NH4+ is a weak acid.

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

A: Yes, a conjugate acid-base pair can be a strong acid and a weak base. For example, HCl (hydrochloric acid) and Cl- (chloride ion) are a conjugate acid-base pair, where HCl is a strong acid and Cl- is a weak base.

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

A: Yes, a conjugate acid-base pair can be a weak acid and a strong base. For example, H2O (water) and OH- (hydroxide ion) are a conjugate acid-base pair, where H2O is a weak acid and OH- is a strong base.

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

A: Conjugate acid-base pairs are essential in understanding acid-base chemistry. They help us understand the behavior of acids and bases, and how they interact with each other.

Q: Can conjugate acid-base pairs be used to predict the pH of a solution?

A: Yes, conjugate acid-base pairs can be used to predict the pH of a solution. By knowing the conjugate acid-base pair of a substance, we can predict its pH.

Q: Can conjugate acid-base pairs be used to predict the concentration of a substance?

A: Yes, conjugate acid-base pairs can be used to predict the concentration of a substance. By knowing the conjugate acid-base pair of a substance, we can predict its concentration.

Conclusion

In conclusion, conjugate acid-base pairs are an essential concept in chemistry. They help us understand the behavior of acids and bases, and how they interact with each other. By understanding conjugate acid-base pairs, we can predict the pH and concentration of a solution.

Key Takeaways

Conjugate acid-base pairs are pairs of substances that differ by one proton (H+ ion).
Acid-base reactions involve the transfer of a proton from an acid to a base.
Conjugate acid-base pairs are essential in understanding acid-base chemistry.
Conjugate acid-base pairs can be used to predict the pH and concentration of a solution.

References

Atkins, P. W., & De Paula, J. (2010). Physical chemistry. Oxford University Press.
Chang, R. (2010). Chemistry: The Central Science. McGraw-Hill.
Petrucci, R. H., Harwood, W. S., & Herring, F. G. (2006). General chemistry: Principles and modern applications. Pearson Prentice Hall.