pH and Hydrogen Ion Concentration Relationship

The concentration of hydrogen ions ($[H^+]$) in a solution is inversely related to its pH value. The relationship is defined by the formula: $pH = -\log_{10}[H^+]$ This means that a lower pH value indicates a higher concentration of hydrogen ions, and conversely, a higher pH value indicates a lower concentration of hydrogen ions.

Analyzing Solution pH Values

We need to find the solution with the highest hydrogen ion concentration. This corresponds to the solution with the lowest pH value among the given options:

• Option 1: pH = 8
• Option 2: pH = 10
• Option 3: pH = 4
• Option 4: pH = 5

Determining Highest Hydrogen Ion Concentration

Comparing the pH values (8, 10, 4, 5), the lowest value is 4. Therefore, the solution with a pH of 4 has the highest concentration of hydrogen ions.