Question

The pH scale was designed to make it convenient to express hydrogen ion concentrations that are small in aqueous solutions. The definiton of pH is in terms of base 10 logarithms.

Answer 1

a. pH = 2.22.

b. [H+] = 2.588 x 10⁻⁴ mol/L.

Step-by-step explanation:

Acids and Bases => Calculating pH of Acids and Bases.

As we saw before, the formulas to find the pH based on the hydrogen ion concentration [H+], and to find the hydrogen ion concentration [H+] based on the pH are the following, respectively:

`\begin{gathered} pH=-log\lbrack H^+], \\ \\ [H^+]=10^(-pH). \end{gathered}`

So let's see each case:

a. To find the pH of an H+ concentration of 6.02 x 10⁻³ mol/L we use the pH formula:

`\begin{gathered} pH=-log\lbrack6.02\cdot10^(-3)], \\ \\ pH=2.220\approx2.22. \end{gathered}`

The answer would be that the pH is 2.22.

b. To find the H+ concentration of a pH of 3.587, we use the [H+] formula:

`\begin{gathered} \lbrack H{}^+]=10^(-3.587), \\ \\ [H^+]=2.5882\cdot10^(-4)\text{ mol/L}\approx2.588\cdot10^(-4)\text{ mol/L.} \end{gathered}`

The answer would be that the hydrogen ion concentration [H+] = 2.588 x 10⁻⁴ mol/L.