Calculate the pH at of a solution of trimethylammonium chloride . Note that trimethylamine is a weak base with a of . Round your answer to decimal place.

pH = 11.9

Explanation:

The solution is 0.93M. The pKb is 4.19

The general equation of a weak base, X, is:

Kb = [OH⁻] [XH⁺] / [X]

Where Kb is 10^-pKb = 6.457x10⁻⁵

[OH⁻] and [XH⁺] comes both from the same equilibrium and its concentration, X, is the same = [OH⁻] = [XH⁺] = X

And [X] could be taken as the initial concentration of the weak acid, 0.93M

Kb = [OH⁻] [XH⁺] / [X]

6.457x10⁻⁵ = X² / 0.93M

6x10⁻⁵ = X²

X = 7.749x10⁻³M = [OH⁻]

As pOH = -log[OH⁻]

pOH = 2.11

pH = 14 - pOH

Option (a) is the correct answer.

Explanation:

Acids are the substances or species which upon dissociation given hydrogen ions, that is, ions.

For example, HF when dissolved in water then it will dissociate into and ions.

Whereas both KOH and are base.

And LiF on dissociation will give and ions.

Therefore, we can conclude that out of the following HF is an acid.