HELP What is the concentration of hydroxide ions (OH−) in a saturated solution of Al(OH)3? The Ksp of Al(OH)3 is 1.8LaTeX: \times×10−33. ?
回答 (2)
2020-04-05 9:55 pm
Al(OH)₃(s) ⇌ Al³⁺(aq) + 3OH⁻(aq) ___ Ksp = 1.8 × 10⁻³³
Initial: ______ 0 M _____ 0 M
Change: ___ +s M ____ +3s M
Eqm: ______ s M _____ 3s
At equilibrium:
Ksp = [Al³⁺] [OH⁻]³
1.8 × 10⁻³³ = s (3s)³
27s⁴ = 1.8 × 10⁻³³
s = ⁴√(1.8 × 10⁻³³/ 27)
s = 2.857 × 10⁻⁹
[OH⁻] = 3 × (2.857 × 10⁻⁹) M = 8.57 × 10⁻⁹ M
The answer: 8.57 × 10⁻⁹ M
Initial: ______ 0 M _____ 0 M
Change: ___ +s M ____ +3s M
Eqm: ______ s M _____ 3s
At equilibrium:
Ksp = [Al³⁺] [OH⁻]³
1.8 × 10⁻³³ = s (3s)³
27s⁴ = 1.8 × 10⁻³³
s = ⁴√(1.8 × 10⁻³³/ 27)
s = 2.857 × 10⁻⁹
[OH⁻] = 3 × (2.857 × 10⁻⁹) M = 8.57 × 10⁻⁹ M
The answer: 8.57 × 10⁻⁹ M
2020-04-05 10:10 pm
In pure water, the concentration of hydroxide ion is already 1 x 10^-7 M.
The value of the answer given (8.57 × 10⁻⁹ M) is almost 12 times LESS that the hydroxide already naturally present.
A better answer (IMO) would be to add 1e-7 and 8.57e-9 and report that as the answer.
The value of the answer given (8.57 × 10⁻⁹ M) is almost 12 times LESS that the hydroxide already naturally present.
A better answer (IMO) would be to add 1e-7 and 8.57e-9 and report that as the answer.
收錄日期: 2021-04-18 18:26:09
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https://hk.answers.yahoo.com/question/index?qid=20200405132320AA5W9yS