Kansas Esthetician Practice Exam 2026 – Complete Study Resource

To understand how much more alkaline a pH of 9 is compared to a pH of 7, it's essential to grasp the logarithmic nature of the pH scale. The pH scale is a measure of hydrogen ion concentration in a solution. A pH of 7 is considered neutral, while lower values indicate acidity and higher values indicate alkalinity.

The pH scale is logarithmic, meaning each whole number change on the scale represents a tenfold change in hydrogen ion concentration. This means that:

- A pH of 8 is ten times more alkaline than a pH of 7.

- A pH of 9 is ten times more alkaline than a pH of 8.

Therefore, from pH 7 to pH 9, there are two increments of 1 (from 7 to 8 and from 8 to 9). Hence, the calculation for the difference is:

10 (for pH 8 compared to pH 7) multiplied by 10 (for pH 9 compared to pH 8) equals 100.

This means a pH of 9 is 100 times more alkaline than a pH of 7.