Question

For the base hydrolysis reaction of a fluoride ion in water, identify the acid/base labels corresponding to each species. (Consider that the Bronsted acid and base are on the reactant side of the equation, and the conjugate acid and conjugate base are on the product side.)

a) Bronsted acid: _______ , Bronsted base: _______
b) Conjugate acid: _______ , Conjugate base: _______

Answer 1

In the reaction F- + H2O = HF + OH-, F- is the Bronsted base and H2O is the Bronsted acid; HF is the conjugate acid and OH- is the conjugate base.

Step-by-step explanation:

In the base hydrolysis reaction of a fluoride ion in water, we have the following species involved:

F− (aq) + H2O (l) ≈ HF (aq) + OH− (aq)

In this case:

• Bronsted acid: H2O
• Bronsted base: F−
• Conjugate acid: HF
• Conjugate base: OH−

This is an example of salt hydrolysis where the fluoride ion, F−, is acting as a weak Brønsted-Lowry base by accepting a proton from water, which in turn, acts as a Brønsted-Lowry acid by donating a proton. The resulting hydroxide ions make the solution slightly basic. The HF and OH− are the conjugate acid and conjugate base, respectively, of the original Bronsted acid and base.