The following pictures represent solutions of three salts NaA (A- = X-, Y-, or Z-); water molecules and Na+ ions have been omitted for clarity.

(a) Arrange the three A- anions in order of increasing base strength.

Verified step by step guidance

1. Identify the anions in each solution: X-, Y-, and Z-.
2. Observe the number of water molecules (H2O) interacting with each anion. More interactions indicate a weaker base.
3. Compare the number of water molecules around each anion. The anion with the most water molecules is the weakest base.
4. Rank the anions from the one with the most water molecules (weakest base) to the one with the fewest water molecules (strongest base).
5. Arrange the anions in order of increasing base strength based on the number of water molecules interacting with them.

Key Concepts

Bronsted-Lowry Acids and Bases

The Bronsted-Lowry theory defines acids as proton donors and bases as proton acceptors. This framework is essential for understanding the behavior of anions in solution, as the strength of a base is determined by its ability to accept protons. In this context, the A- anions (X-, Y-, Z-) will vary in their basicity based on their structure and the stability of the resulting conjugate acid.

Base Strength and Stability of Conjugate Acids

The strength of a base is inversely related to the stability of its conjugate acid. A more stable conjugate acid indicates a weaker base, as it is less likely to donate a proton. When comparing the A- anions, understanding the factors that influence the stability of their conjugate acids, such as electronegativity and resonance, is crucial for determining their relative base strengths.

Electronegativity and Resonance

Electronegativity refers to the tendency of an atom to attract electrons, which affects the distribution of charge in a molecule. In the context of anions, higher electronegativity can lead to greater stability of the conjugate acid. Additionally, resonance structures can delocalize charge, further stabilizing the conjugate acid. Both factors are key in assessing the basicity of the A- anions in the question.