pH Scale
What is the pH scale?
The pH scale is a measure of how acidic or basic a chemical substance is.
- A pH of 7 is netural
- A pH less than 7 is acidic
- A pH greater than 7 is basic
| Strength | strong acids | weak acids | neutral | weak bases | strong bases |
| pH | 0-2 | 3-6 | 7 | 8-10 | 11-14 |
| Examples | Car acid batteries | Lemon juice | Water | Toothpaste | Oven cleaner |
Each pH unit changes in strength by a factor of 10.
An acid of pH 1 is 1000 times stronger than an acid of pH 4.
A base of pH 14 is 100 times stronger than a base of pH 12.
The pH is a logarithmic measure of the concentration of hydrogen ions, H+ in solution.
Chemists use the formula pH = -log10[H+] to determine the pH of a substance.