ATI TEAS (Test of Essential Academic Skills) Version 7ScienceHard
A chemist is analyzing a sample and detects a substance with a pH of 12.5. Based on this measurement, which of the following statements is true about the substance?
- AIt is a strong acid.
- BIt is a weak acid.
- CIt is a strong base.
- DIt is a neutral solution.
Show answer & explanationAnswer & explanation
Correct answer: C. It is a strong base.
A pH of 12.5 indicates a highly alkaline (basic) solution. Solutions with a pH significantly above 7 are basic, and a pH of 12.5 is far from neutral (pH 7) and very high, characteristic of a strong base.
Why the other options are wrong
- A. Strong acids have a very low pH, typically 0-2.
- B. Weak acids have a pH between 2 and 7.
- D. Neutral solutions have a pH of exactly 7.
pH Scale
A logarithmic scale used to specify the acidity or alkalinity of an aqueous solution.
- Ranges from 0 to 14.
- pH 7 is neutral.
- Lower pH indicates higher acidity, higher pH indicates higher alkalinity (basicity).
Memory trick: High pH means 'hyper-basic'.