The pH of the substance is 3.
Explanation:
Given:
Concentration of hydrogen ion, [H⁺] = 10⁻³M
pH = ?
The pH of a solution is a measure of the molar concentration of hydrogen ions in the solution and as such is a measure of the acidity or basicity of the solution.
pH = -log [H⁺]
pH = -log [10⁻³]
pH = 3 log [10]
pH = 3
The pH of the substance is 3 and since the pH is less than 7, the substance is acidic in nature.
