An unknown base (B⁻) has been identified as very weak. What does this tell you about the strength of its conjugate acid, HB? Is it stable or unstable? Is it reactive or unreactive?

Verified step by step guidance

1. Step 1: Recall the relationship between the strength of a base and its conjugate acid. A very weak base corresponds to a very strong conjugate acid. This is because the ability of the base to accept a proton is inversely related to the ability of its conjugate acid to donate a proton.
2. Step 2: Analyze the stability of the conjugate acid (HB). Strong acids tend to be stable because they readily donate protons and form stable conjugate bases. Therefore, if the base (B⁻) is very weak, its conjugate acid (HB) is likely stable.
3. Step 3: Consider the reactivity of the conjugate acid (HB). Strong acids are highly reactive because they easily donate protons in chemical reactions. Since HB is a strong acid, it is expected to be reactive.
4. Step 4: Summarize the findings: A very weak base (B⁻) indicates that its conjugate acid (HB) is strong, stable, and reactive.
5. Step 5: Apply this concept to other acid-base pairs to understand how the strength of a base influences the properties of its conjugate acid in various chemical contexts.

Key Concepts

Conjugate Acid-Base Relationship

In acid-base chemistry, a conjugate acid is formed when a base accepts a proton (H⁺). The strength of a base is inversely related to the strength of its conjugate acid; thus, if a base is very weak, its conjugate acid is likely to be strong. This relationship is fundamental in predicting the behavior of acids and bases in chemical reactions.

Stability of Conjugate Acids

The stability of a conjugate acid is influenced by its ability to stabilize the positive charge that results from protonation. A weak base typically forms a stable conjugate acid because the conjugate acid does not readily donate the proton back, indicating that it is less reactive. Stability often correlates with the presence of electronegative atoms or resonance structures that can delocalize charge.

Reactivity of Acids and Bases

Reactivity in acid-base chemistry refers to how readily an acid donates protons or a base accepts them. A weak base, such as B⁻, suggests that its conjugate acid, HB, is unreactive, as it does not easily release protons. This unreactivity is a characteristic of stable conjugate acids, which do not participate in further acid-base reactions under standard conditions.