Given that Kb for ammonia is 1.8 * 10-5 and that for hydroxylamine is 1.1 * 10-8, which is the stronger base?

Key Concepts

Base Strength

Base strength refers to the ability of a substance to accept protons (H+) or donate electron pairs. In aqueous solutions, stronger bases have a higher tendency to dissociate and produce hydroxide ions (OH-). The strength of a base can be quantitatively expressed using the base dissociation constant (Kb), where a larger Kb value indicates a stronger base.

Base Dissociation Constant (Kb)

The base dissociation constant (Kb) is a measure of the extent to which a base dissociates in water to form hydroxide ions and its conjugate acid. It is calculated from the equilibrium concentrations of the products and reactants in the dissociation reaction. A higher Kb value signifies a stronger base, as it indicates a greater degree of ionization in solution.

Comparative Analysis of Kb Values

To determine which base is stronger between two bases, one can compare their Kb values directly. The base with the larger Kb value is considered the stronger base. In this case, ammonia (Kb = 1.8 * 10^-5) has a higher Kb than hydroxylamine (Kb = 1.1 * 10^-8), indicating that ammonia is the stronger base.