NIC Cosmetology Written (Theory) ExamScientific ConceptsMedium
When performing a chemical service that requires a specific pH level for optimal results, a cosmetologist needs to understand how to adjust the acidity or alkalinity of a solution. Which of the following pH values indicates a solution that is alkaline?
- A9.0
- B5.0
- C3.5
- D7.0
Show answer & explanationAnswer & explanation
Correct answer: A. 9.0
The pH scale ranges from 0 to 14. A pH of 7 is neutral. Values below 7 are acidic, and values above 7 are alkaline (or basic). Therefore, a pH of 9.0 indicates an alkaline solution.
Why the other options are wrong
- B. A pH of 5.0 is acidic.
- C. A pH of 3.5 is acidic.
- D. A pH of 7.0 is neutral.
pH Scale
A logarithmic scale (0-14) used to specify the acidity or alkalinity of an aqueous solution, with 7 being neutral, values below 7 being acidic, and values above 7 being alkaline (basic).
- Scale from 0 to 14
- 0-6.9 is acidic
- 7.0 is neutral
- 7.1-14 is alkaline (basic)
- Logarithmic scale (each whole number represents a tenfold change)
Memory trick: Acidic is A-low, Alkaline is A-high