Conjugated Acids of Bronsted Bases

Introduction

In acid-base chemistry, the concept of conjugate acids and bases is fundamental to understanding how substances interact in chemical reactions. A conjugate acid is formed when a Bronsted base accepts a proton (H⁺). For each Bronsted base, the conjugated acid can be determined by adding a proton to the base.

1. Conjugated Acid of NH₂⁻ (Amide Ion)

• Bronsted Base: NH₂⁻ (Amide Ion)
• Conjugated Acid: To find the conjugated acid, add a proton (H⁺) to NH₂⁻.

  $2_{-}^{}+{+}^{}\to 3_{}\backslash text\{NH\}\_2^-\; +\; \backslash text\{H\}^+\; \backslash rightarrow\; \backslash text\{NH\}\_3$NH2−​+H+→NH3​

• Conjugated Acid: NH₃ (Ammonia)
  • Example: NH₃ is commonly used in the Haber process for synthesizing ammonia from nitrogen and hydrogen gases. In this reaction, NH₂⁻ accepts a proton to form NH₃.

2. Conjugated Acid of NH₃ (Ammonia)

• Bronsted Base: NH₃ (Ammonia)
• Conjugated Acid: To find the conjugated acid, add a proton (H⁺) to NH₃.

  $3_{}+{+}^{}\to 4_{+}^{}\backslash text\{NH\}\_3\; +\; \backslash text\{H\}^+\; \backslash rightarrow\; \backslash text\{NH\}\_4^+$NH3​+H+→NH4+​

• Conjugated Acid: NH₄⁺ (Ammonium Ion)
  • Example: NH₄⁺ is formed when ammonia acts as a base in aqueous solutions. It is commonly found in ammonium chloride (NH₄Cl), which is used in fertilizers and as a food additive.

3. Conjugated Acid of HCOO⁻ (Formate Ion)

• Bronsted Base: HCOO⁻ (Formate Ion)
• Conjugated Acid: To find the conjugated acid, add a proton (H⁺) to HCOO⁻.

  ${-}^{}+{+}^{}\to HCOOH\backslash text\{HCOO\}^-\; +\; \backslash text\{H\}^+\; \backslash rightarrow\; \backslash text\{HCOOH\}$HCOO−+H+→HCOOH

• Conjugated Acid: HCOOH (Formic Acid)
  • Example: HCOOH is used in various industrial processes and as a preservative. It is formed when the formate ion (HCOO⁻) accepts a proton, making it a key player in formic acid solutions.

Conclusion

The conjugated acids for the given Bronsted bases are:

• NH₂⁻ (Amide Ion) → NH₃ (Ammonia)
• NH₃ (Ammonia) → NH₄⁺ (Ammonium Ion)
• HCOO⁻ (Formate Ion) → HCOOH (Formic Acid)

These conjugate acids play significant roles in various chemical processes and applications. Understanding their formation helps in grasping the principles of acid-base reactions and their practical implications in chemistry.