Ph From Concentration
Calculator
Results
- pH
- 4
- pOH
- 10
- OH⁻ concentration (mol/L)
- 9.999999999999999e-11
Chemistry results
| pH | 4 |
| pOH | 10 |
| OH⁻ concentration (mol/L) | 9.999999999999999e-11 |
formula-map diagram
- pH
- 4
- pOH
- 10
- OH⁻ concentration (mol/L)
- 9.999999999999999e-11
Formula breakdown
Formula
pH = −log₁₀[H⁺]= 4
Note
Simplified model: these results assume ideal behaviour (ideal gases, dilute solutions, complete reactions) and standard textbook constants. Real laboratory values vary with temperature, pressure, purity and activity coefficients. Do not rely on this for safety-critical or analytical work.
More in Chemistry
See all →Frequently asked questions
How is pH calculated from hydrogen ion concentration?+
pH is the negative base-10 logarithm of the hydrogen ion concentration: pH = -log10[H+]. A concentration of 1 x 10^-7 mol/L gives a pH of 7, which is neutral at 25°C.
Why does a lower pH mean a more acidic solution?+
Because pH is an inverse logarithmic scale of [H+], a higher hydrogen ion concentration produces a smaller (or more negative) logarithm result, so more acidic solutions have lower pH values. Each one-unit drop in pH represents a tenfold increase in [H+].
What's the difference between a pH of 3 and a pH of 5?+
The pH scale is logarithmic, so a solution with pH 3 has 100 times more hydrogen ions than one with pH 5, not just 40% more. This is a frequent misconception — pH differences must be interpreted as powers of ten, not linear differences.
Can pH be negative or above 14?+
Yes, in very concentrated strong acids or bases the formula can produce pH values below 0 or above 14, since the 0-14 range is just the typical range for dilute aqueous solutions, not a hard mathematical limit. Extremely concentrated solutions also stop behaving ideally, so measured pH can diverge from the simple formula.
Does temperature affect the pH of a neutral solution?+
Yes — pure water's neutral pH of exactly 7 only holds at 25°C; at higher temperatures, water's self-ionization increases, pushing neutral pH slightly below 7, even though the solution is still neutral (equal H+ and OH- concentrations).