A buffer solution is made when 1.50 g of sodium hydroxide are added to 1.00 dm3 of a 0.150 mol dm–3 solution of a weak acid HA.
For HA, the acid dissociation constant, Ka = 1.79 × 10−5 mol dm−3.
Calculate the pH of this buffer solution.
What is the pH of this buffer solution?
2020-05-06 5:41 am
回答 (1)
2020-05-06 12:45 pm
✔ 最佳答案
Ka = 1.79X10^-5 = [H+][A-]/[HA]Initial moles HA = 0.150 mol
moles NaOH added = 1.50 g / 40.0 g/mol = 0.0375 mol
The NaOH quantitatively neutralizes HA forming A-. So, after the addition,
moles A- = 0.0375
moles HA = 0.150 - 0.0375 = 0.1125
1.79X10^-5 = [H+](0.0375)/(0.1125)
[H+] = 5.37X10^-5
pH = 4.270
收錄日期: 2021-04-24 07:49:01
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