Question

Pure water has a hydrogen ion concentration of 1 × 10−7 M and a pH of 7. A student measures a basic solution and finds that it has a hydrogen ion (H+) concentration of 1 × 10−3. Explain why the student must have made an error in her measurement.

Answer 1

Basic solutions have pH>7.

pH= -log [H⁺] = - log[10⁻³] = 3
pH=3
pH = 3 is less than 7, that means that solution should be acidic, that is wrong because a student was measuring basic solution, So, she made an error in her measurement.