NIC Cosmetology Written (Theory) ExamScientific ConceptsMedium
Which of the following describes a substance that has a pH of 8.5?
- AWeak acid
- BAlkaline solution
- CStrong acid
- DNeutral solution
Show answer & explanationAnswer & explanation
Correct answer: B. Alkaline solution
The pH scale ranges from 0 to 14. A pH of 7 is neutral. A pH below 7 is acidic, and a pH above 7 is alkaline (or basic). Therefore, a substance with a pH of 8.5 is an alkaline solution, specifically a weak alkaline solution.
Why the other options are wrong
- A. Weak acids have a pH between 2 and 6.9.
- C. Strong acids have a pH typically between 0 and 2.
- D. A neutral solution has a pH of exactly 7.
pH Scale
A scale used to specify the acidity or alkalinity of an aqueous solution.
- Ranges from 0 to 14.
- pH 7 is neutral (e.g., pure water).
- pH below 7 is acidic; pH above 7 is alkaline (basic).
Memory trick: pH 'Powers' 'Hydrogen' – 'Seven' is 'Heaven'!