PSI Barbering Practice Exam

What color change occurs to blue litmus paper in the presence of acids?

1. It turns yellow

2. It remains blue

3. It turns red

4. It turns green

The correct answer is: It turns red

In the presence of acids, blue litmus paper undergoes a color change to red. This is due to the acid's nature, which has a pH level below 7. Litmus paper is a pH indicator that helps determine the acidity or basicity of a solution; blue litmus paper specifically indicates that a solution is neutral or basic. When it comes into contact with an acidic solution, the chemical composition of the litmus dye changes, resulting in a red coloration. Understanding this color change is crucial for anyone practicing in fields such as chemistry and barbering, where the knowledge of pH levels may apply in various contexts, such as understanding different hair products and their effects on hair and scalp condition.