Calculating The pH of Solutions

Question

Calculate the pH of each of the following solutions, and label each as acidic, basic, or neutral.

Solution

1.) [H₃O⁺] = 1.0 × 10^-9 M

2.) [H₃O⁺] = 0.001 M

3.) [H₃O⁺] = 3.7 × 10^-6 M

Answer 1

pH = -log [H3O+]

1) pH = -log 1.0x10-9 = 9 (basic)

2) pH = -log 0.001 = 3 (acidic)

3) pH = -log 3.7x10-6 = 5.4 (acidic)