Calculating pH of a Solution

Understanding pH Calculation

pH is the measure of acidity of a solution based on the concentration of H⁺ ions present. The pH scale ranges from 0 to 14, where values below 7 are considered acidic, 7 is neutral, and values above 7 are alkaline. pH is calculated using the formula: pH = -log[H⁺]. This means that as the concentration of H⁺ ions increases, the pH value decreases, indicating higher acidity.

Mathematical Calculation for pH

Given that the solution has a [H+] of 0.20 M, we can calculate the pH as follows:

pH = -log[0.2]

pH = 1 - log 2

pH = 0.699

Understanding the Inverse Relationship

The relationship between pH and the concentration of H⁺ ions is inverse, meaning that as pH decreases, the concentration of H⁺ ions increases. For every unit change in pH, there is a 10-fold change in the concentration of H⁺ ions.

Therefore, in the given solution with a [H+] of 0.20 M, the calculated pH of 0.699 indicates a moderately acidic nature of the solution.