# Logarithmic scale: pH scale

### Logarithmic scale: pH scale

In this section, we will bridge the gap between chemistry and mathematics by studying one of the many applications of logarithmic functions. We will learn about the pH Scale and explore how this logarithmic scale can be used to measure the acidity or basicity of a solution.

#### Lessons

• 1.
Pure water has a pH of 7. Vinegar has a pH of 3.
Complete the following 2 sentences:
(i) Pure water is __________ times as alkaline as vinegar.
(ii) Vinegar is __________ times as acidic as pure water.

• 2.
Lemon juice has a pH of 2.5.
Stomach acid is 8 times more acidic than lemon juice.
Tomato juice is 90 times more basic than lemon juice
Find the pH of:
(i)
stomach acid
(ii) tomato juice