Question

What is an example of a pH practice problem?

Answer 1

Generally, most pH problems ask you to determine pH from `[H^+]` the hydrogen ion concentration,or conversely, determine the `[H^+]` from the pH.

Let's look at the strong acid HCl, hydrochloride acid, which has a concentration of 0.1 molar.

In aqueous solutions, hydrochloric acid dissociates into hydrogen and chloride ions.

HCl `->` `H^+` + `Cl^-`

Because there is a one to one ratio between the acid and the hydrogen ion, the `[H^+]` is 0.1 molar.

Now convert the hydrogen ion concentration to pH using the equation pH = -log `[H^+]`

Applying this to our problem

pH = -log `[H^+]`
pH = -log [0.1]
pH = 1

To reverse the problem from pH to [H+]
Use the equation
[H+] = antilog(-pH)