a. which of the following can behave as bronsted-lowry bases in aqueous solution?
- koh
naoh
ca(oh)2 - f^-
none of the above
b. write the net ionic equation for the acid-base hydrolysis equilibrium that is established when barium fluoride is dissolved in water. (use the lowest possible coefficients. be sure to specify states such as (aq) or (s). if a box is not needed, leave it blank) h2o (1) –> + +
this solution is: acidic, basic, neutral
The Correct Answer and Explanation is :
Part a: Bronsted-Lowry Bases in Aqueous Solution
A Bronsted-Lowry base is defined as a substance that accepts protons (H⁺ ions) in an aqueous solution. Let’s go through the substances one by one to see which can behave as Bronsted-Lowry bases:
- KOH (Potassium Hydroxide):
KOH dissociates in water to form K⁺ and OH⁻ ions. The OH⁻ ion can accept a proton, so KOH can act as a Bronsted-Lowry base. - NaOH (Sodium Hydroxide):
Similar to KOH, NaOH dissociates in water to form Na⁺ and OH⁻ ions. The OH⁻ ion can accept a proton, so NaOH is also a Bronsted-Lowry base. - Ca(OH)₂ (Calcium Hydroxide):
Ca(OH)₂ dissociates in water to produce Ca²⁺ and OH⁻ ions. As with KOH and NaOH, the OH⁻ ion acts as a Bronsted-Lowry base, so Ca(OH)₂ can also behave as a Bronsted-Lowry base. - F⁻ (Fluoride ion):
The fluoride ion is the conjugate base of HF (hydrofluoric acid). When F⁻ accepts a proton (H⁺), it forms HF. Thus, F⁻ can also behave as a Bronsted-Lowry base.
Answer to Part a:
- KOH, NaOH, Ca(OH)₂, and F⁻ can all behave as Bronsted-Lowry bases in aqueous solution.
Part b: Net Ionic Equation for Barium Fluoride Dissolution
When Barium Fluoride (BaF₂) dissolves in water, it dissociates into Ba²⁺ and F⁻ ions. The fluoride ion (F⁻), being the conjugate base of a weak acid (HF), will undergo hydrolysis to react with water, forming hydroxide ions (OH⁻) and hydrofluoric acid (HF).
The relevant equilibrium for this reaction is:
[ F^-(aq) + H_2O(l) \rightleftharpoons HF(aq) + OH^-(aq) ]
Net Ionic Equation:
[ F^-(aq) + H_2O(l) \rightleftharpoons HF(aq) + OH^-(aq) ]
Solution Type
Since the fluoride ions accept protons from water and produce OH⁻ ions, the solution will be basic.
Explanation:
- Barium Fluoride Dissolution: When BaF₂ dissolves in water, it dissociates as:
[
BaF_2(s) \rightarrow Ba^{2+}(aq) + 2F^-(aq)
] - Hydrolysis Reaction: The fluoride ions (F⁻) are basic and can react with water molecules in an acid-base reaction:
[
F^-(aq) + H_2O(l) \rightleftharpoons HF(aq) + OH^-(aq)
] In this reaction, the fluoride ion (F⁻) accepts a proton (H⁺) from water, producing hydroxide ions (OH⁻) and hydrofluoric acid (HF). - Basic Nature of the Solution: The production of OH⁻ ions increases the pH of the solution, making it basic.
Image Generation
I will now generate an image that visually represents the dissolution and hydrolysis process.
Here is the image illustrating the dissolution of barium fluoride (BaF₂) in water and the subsequent hydrolysis of fluoride ions (F⁻) with water to form HF and OH⁻. It visually represents the basic nature of the resulting solution. Let me know if you need further details!
