pH

pH-Wert
(potentia hydrogenii - „Stärke des Wasserstoffs“, „power of hydrogen“)

It declares the concentration of hydrogen ions in a solution and is defined as the negative decadic logarithm of hydrogen ion concentration.

pH = -lg [H+]

Annotation: [H+] is the symbol for the hydrogen ion concentration.

Neutral solution:

[H+] , pH

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|solved

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or

when the solution of a hydrogen ion concentration amounts e.g. , then the pH value is 3.

• pH < 7 signifies an acid solution (on a scale of 0 to 14)
• pH = 7 signifies a neutral solution
• pH > 7 signifies an alkaline solution (on a scale of 0 to 14)

Implication:

So, the closer the pH to the pH of 7, the lower the strength of the acid or the alkali respectively.

Examples:

• ordinary hydrochloride acid has the pH value of 0 (acid).
• ordinary potassium hydrochloride solution has the pH value of 14 (alkali).

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