It is inconvenient to express concentration of hydrogen ions as a number with many zeros right after the decimal point, e.g., H+ = 0.00000048 N. Instead we define pH as the negative logarithm of the hydrogen ion concentration, and the clumsy number just used becomes pH = 6.32. Pocket calculators convert concentration to pH merely by entering the concentration, invoking the logarithm (base 10) function, and changing the sign. The reverse operation requires entering the pH, raising ten to that power, and taking the reciprocal.

Enter pH H+ =
or enter concentration of hydrogen ions pH =

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