Hydrogen Ion Concentration Calculator

The Hydrogen Ion Concentration Calculator converts between pH, pOH, and hydrogen ion concentration $[H^+]$ in aqueous solutions at 25 °C.

$$pH = -\log_{10}([H^+])$$

$$[H^+] = 10^{-pH}$$

At 25 °C, pH and pOH are related by:

$$pH + pOH = 14$$

Example: a solution with pH = 3.5 has $[H^+] = 10^{-3.5} = 3.16 \times 10^{-4}$ mol/L and pOH = 10.5.

pH below 7 indicates an acidic solution, pH above 7 is basic, and pH = 7 is neutral. Each unit decrease in pH means a tenfold increase in hydrogen ion concentration.

Frequently Asked Questions

How do I find hydrogen ion concentration from pH?

Use [H+] = 10^(-pH). For pH = 3.5, [H+] = 10^(-3.5) = 3.16 × 10^-4 mol/L.

What is the relationship between pH and pOH?

At 25 °C, pH + pOH = 14. If you know one value, subtract it from 14 to get the other.

Do acids have more hydrogen ions?

Yes. Acidic solutions have higher [H+] and lower pH than neutral water (pH 7). Stronger acids produce even higher hydrogen ion concentrations.

What does a pH of 6.5 mean?

pH 6.5 is slightly acidic. [H+] = 10^(-6.5) = 3.16 × 10^-7 mol/L, which is about 3 times more acidic than pure water.

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Hydrogen Ion Concentration Calculator

Hydrogen Ion Concentration Calculator

Frequently Asked Questions

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