pH is defined as the negative logarithmic function of the hydronium ion concentration.
In simple language: pH measures the amount of acid (H) and hydroxide (OH) in water.
Pure water is composed of hydrogen (H) and hydroxide (OH) ions. When they are in perfect balance, pure water is formed (H2O) and both are present at 10-7 gram equivalents (or moles) per liter. The water has a pH of 7, which is neutral.
As the concentration of hydrogen (H) varies, the concentration of OH must also vary, but in the opposite direction. By reacting in opposite directions the product of the two ions remains constant. Below is a table that demonstrates hydrogen (H) and hydroxide (OH) ions at different pH’s”
| pHa |
H+ Concentration Exponential Notation, gram moles/L |
H+ Concentration, Normality |
OH – Concentration, Normality |
OH –Concentration, Exponential Notation, gram moles/L |
| 0 |
100 |
1 | 0.00000000000001 |
10-14 |
| 1 |
10-1 |
0.1 | 0.0000000000001 |
10--13 |
| 2 |
10-2 |
0.01 | 0.000000000001 |
10--12 |
| 3 |
10-3 |
0.001 | 0.00000000001 |
10-11 |
| 4 |
10-4 |
0.0001 | 0.0000000001 |
10-10 |
| 5 |
10-5 |
0.00001 | 0.000000001 |
10-9 |
| 6 |
10-6 |
0.000001 | 0.00000001 |
10-8 |
| 7 |
10-7 |
0.0000001 | 0.0000001 |
10-7 |
| 8 |
10-8 |
0.00000001 | 0.000001 |
10-6 |
| 9 |
10-9 |
0.000000001 | 0.00001 |
10-5 |
| 10 |
10-10 |
0.0000000001 | 0.0001 |
10-4 |
| 11 |
10-11 |
0.00000000001 | 0.001 |
10-3 |
| 12 |
10-12 |
0.000000000001 | 0.01 |
10-2 |
| 13 |
10-13 |
0.0000000000001 | 0.1 |
10-1 |
| 14 |
10-14 |
0.00000000000001 | 1 |
100 |
Common solution pH levels:
| 12 | OH – alkalinity 500 ppm as CaCO3 |
| 11 | OH – alkalinity 50 ppm as CaCO3 |
| 10 | OH – alkalinity 5 ppm as CaCO3 |
| 9 | B-86 boiler water treatment |
| 8 | phenolphthalein end point |
| 7 | neutral point at 25 °C |
| 6 | |
| 5 | methyl orange end point |
| 4 | FMA 4 ppm as CaCO3 |
| 3 | FMA 40 ppm as CaCO3 |
| 2 | FMA 400 ppm as CaCO |
IBH Labs brings you the water treatment technology you need at a price you can afford