Question

Suppose that the pH meter indicates that the pH of three solutions is 2.00, 7.15, and 10.50, respectively. Calculate the [H,O'] of each of these solutions in molarity 7. Calculate the pH of a 0.10M HOAc (acetic acid) solution.

Answer 1

The hydronium ion concentrations for pH values 2.00, 7.15, and 10.50 are 0.01 M, approximately 7.08 x 10^-8 M, and 3.16 x 10^-11 M, respectively. The pH of a 0.10M HOAc solution is 2.879.

Step-by-step explanation:

To calculate the hydronium ion concentration [H3O+] for each solution given the pH values:

• pH 2.00: [H3O+] = 10-2.00 M = 0.01 M
• pH 7.15: [H3O+] = 10-7.15 M ≈ 7.08 x 10-8 M
• pH 10.50: [H3O+] = 10-10.50 M = 3.16 x 10-11 M

For the calculation of the pH of a 0.10M HOAc (acetic acid) solution:

[H3O+] = 1.32 x 10-3 M

pH = -log(1.32 x 10-3) = 2.879

Remember, the pH is indicative of an acidic solution, and the corresponding hydroxide-ion concentration for any pH can be found using the relation [OH-] = 10-14 / [H3O+].