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A weak acid HA has pKa = 4.80 and a weak base BOH has pKb = 4.78. What will be the pH of an aqueous solution of the salt BA formed from them?
- 9.58
- 4.79
- 7.01
- 9.22
Correct answer: 7.01
Solution
For salt BA: pH = 7 + 0.5(pKa - pKb) = 7 + 0.5(4.80 - 4.78) = 7 + 0.01 = 7.01. So the solution is essentially neutral, pH = 7.01.
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