Identify the stronger base in each of the following pairs.
Explain your reasoning.
(a) ClO₂^- or ClO₃^-
(b) HSO₄^- or HSeO₄^-

Verified step by step guidance

1. Identify the conjugate acids of the given bases: ClO_2^- and ClO_3^-.
2. Recall that the strength of a base is inversely related to the strength of its conjugate acid.
3. Compare the acid strengths of HClO_2 and HClO_3.
4. Note that HClO_3 is a stronger acid than HClO_2 due to the higher oxidation state of chlorine, which stabilizes the conjugate base ClO_3^-.
5. Conclude that ClO_2^- is the stronger base because its conjugate acid, HClO_2, is weaker than HClO_3.

Key Concepts

Acid-Base Theory

Acid-base theory explains the behavior of acids and bases in chemical reactions. According to the Brønsted-Lowry theory, acids are proton donors and bases are proton acceptors. Understanding this concept is crucial for determining the strength of a base, as stronger bases are more effective at accepting protons.

Conjugate Acid-Base Pairs

Conjugate acid-base pairs consist of two species that differ by the presence or absence of a proton (H+). When a base accepts a proton, it forms its conjugate acid. Analyzing the conjugate pairs helps in understanding which base is stronger, as the strength of a base is inversely related to the strength of its conjugate acid.

Electronegativity and Stability

Electronegativity refers to the tendency of an atom to attract electrons in a bond. In the context of oxyanions like ClO2- and ClO3-, the stability of the resulting conjugate acids (HClO2 and HClO3) is influenced by the electronegativity of the central atom and the number of oxygen atoms. A more stable conjugate acid indicates a weaker base, thus helping to identify the stronger base in the pair.