Question

1. for two bases of equal concentration, the weaker base has —

a lower concentration of hydroxide ions.

a higher ph.

a lower concentration of hydronium ions.

a weaker bond.

clear all

Explanation:

A weak base ionizes less in solution compared to a strong base of the same concentration. Hydroxide ions ($\ce{OH^-}$) are produced by the ionization of bases. So, a weaker base will produce fewer $\ce{OH^-}$ ions. Let's analyze each option:

• Option 1: A lower concentration of hydroxide ions. Since a weak base ionizes less, it produces fewer $\ce{OH^-}$ ions. This is correct.
• Option 2: A higher pH. pH is related to the concentration of $\ce{H^+}$ (or $\ce{H3O^+}$) ions. A higher concentration of $\ce{OH^-}$ (from a strong base) leads to a higher pH (more basic). A weak base has fewer $\ce{OH^-}$ ions, so its pH is lower than a strong base of the same concentration. So this is incorrect.
• Option 3: A lower concentration of hydronium ions. Hydronium ions ($\ce{H3O^+}$) are related to acidity. The concentration of $\ce{H3O^+}$ and $\ce{OH^-}$ are inversely related ($K_w = [\ce{H3O^+}][\ce{OH^-}]$). A weak base has fewer $\ce{OH^-}$ ions, so it should have a higher concentration of $\ce{H3O^+}$ (since $K_w$ is constant at a given temperature). So this is incorrect.
• Option 4: A weaker bond. The strength of a base is related to its ability to accept protons (or ionize to produce $\ce{OH^-}$), not directly to the strength of its bonds in the way this option implies. So this is incorrect.

Answer:

A. a lower concentration of hydroxide ions.