HELP WITH CHEM!!!!?

2018-03-22 8:28 pm

Really confused, please include how to get there too:)

At what concentration of ammonia is :

A. [Co^+3] = [Co(NH3)6^+3]? Kf=1.00 x 10^23

B. [Ag^+1] = [Ag(NH3)2^+1] Kf=1.70 x 10^7

回答 (1)

胡雪8°

2018-03-22 9:31 pm

A.
Co³⁺(aq) + 6NH₃(aq) ⇌ Co(NH₃)₆³⁺(aq) …. Kf = 1.00 × 10²³

Kf = [Co(NH₃)₆³⁺] / ([Co³⁺] [NH₃]⁶) = 1.00 × 10²³

When [Co³⁺] = [Co(NH₃)₆³⁺]:
1 / [NH₃]⁶ = 1.00 × 10²³
[NH₃] = {1 / (1.00 × 10²³)}^(1/6) M = 1.47 × 10⁻⁴ M

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B.
Ag⁺(aq) + 2NH₃(aq) ⇌ Ag(NH₃)₂⁺(aq) …. Kf = 1.70 × 10⁷

Kf = [Ag(NH₃)₂⁺] / ([Ag⁺] [NH₃]²) = 1.70 × 10⁷

When [Ag⁺] = [Ag(NH₃)₂⁺]:
1 / [NH₃]² = 1.70 × 10⁷
[NH₃] = √{1 / (1.70 × 10⁷)} M = 2.43 × 10⁻⁴ M

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