Question

What effect does the presence of dissolved sodium fluoride have on the dissociation equilibrium of hydrofluoric acid? (select all three that apply)...

The percent dissociation of HF is reduced by the presence of dissolved NaF.
THe pH of the solution containing NaF and HF would be higher than that of a solution of HF only.
The presence of NaF drives the reaction towards the HF side to reach equilibrium.
The concentration of H+ is higher in an HF solution containing NaF.
The pH of the solution containing NaF and HF would be lower than that of a solution of HF only.
The presence of the dissolved NaF does not affect the HF equilibrium reaction nor the equilibrium concentrations.

Answer 1

Dissolved sodium fluoride reduces the percent dissociation of hydrofluoric acid, increases the pH of the solution, and drives the reaction towards the HF side to reach equilibrium.

Step-by-step explanation:

The effect of dissolved sodium fluoride on the dissociation equilibrium of hydrofluoric acid

When sodium fluoride (NaF) is dissolved in hydrofluoric acid (HF), it affects the dissociation equilibrium in the following ways:

1. The percent dissociation of HF is reduced by the presence of dissolved NaF. This means that less HF molecules will break apart into ions, resulting in fewer hydronium ions (H+) and fluoride ions (F-) in the solution.
2. The pH of the solution containing NaF and HF would be higher than that of a solution of HF only. The hydroxide ion produced when F- accepts a proton makes the solution slightly basic.
3. The presence of NaF drives the reaction towards the HF side to reach equilibrium. This is because the addition of F- shifts the equilibrium of HF dissociation to the left, reducing the concentration of H+ and F- ions.

Therefore, the correct options are: The percent dissociation of HF is reduced by the presence of dissolved NaF, The pH of the solution containing NaF and HF would be higher than that of a solution of HF only, and The presence of NaF drives the reaction towards the HF side to reach equilibrium.

Answer 2

The correct answer for the question that is being presented above is this one: "The pH of the solution containing NaF and HF would be lower than that of a solution of HF only.; THe pH of the solution containing NaF and HF would be higher than that of a solution of HF only."