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How do you calculation pH from ka?

Updated: 11/4/2023
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Wiki User

14y ago

Best Answer

Ka = [H+][A-] / [HA]

Hence

[H+] = Ka[HA] / [A-]

Remember pH = -log(10)[H+]

'logging' both sides.

-log(10)[H+] = - log(10)Ka[HA] / [A-]

By algebraic manipulation of log.

pH = -log[A-]^-1 - logKa - log[HA]

pH = log[A-] - logKa - log[HA]

pH = pKa - log[HA]/[A-]

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lenpollock

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6mo ago
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11y ago

pH = pKa + log([A-]/[HA])

pH = pKa+log([conjugate base]/[undissociated acid])

pKa is also a measure of the strength of an acid. A low pKa is a strong acid, a higher pKa is a weak acid.

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11y ago

Calculate the pH of a 0.010 M solution of Acetic Acid

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Anonymous

Lvl 1
3y ago
I only see a question.

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Wiki User

8y ago

The equation is:
pH = pKa - log[AH]/[A-]
where
- [AH] is the acid concentration
- [A-] is the conjugate base concentration

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14y ago

pH = pKa + log[A]/[HA]

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12y ago

Yes.

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