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Topic: Precipitation in buffer solution  (Read 2360 times)

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Offline Mimic

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Precipitation in buffer solution
« on: January 17, 2017, 04:38:22 PM »
In 500 ml of a Co(OH)2 saturated solution (Kps = 1.6*10-18) are introduced 0.1 mol of NH3 and 0.3 mol of NH4Cl. The constant of ammonia dissociation is 1.8*10-5: what is the amount by weight of hydroxide which precipitates?

Can you help me?

Thanks in advance

Offline AWK

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Re: Precipitation in buffer solution
« Reply #1 on: January 18, 2017, 12:34:31 AM »
1. Calculate solubility of cobalt(II) hydroxide in water.
2. Calculate concentration of OH- in buffer solution.
3. Calculate solubility cobalt(II) hydroxide at this concentration of OH-.
4. Calculate difference of solubilities (expressed in molar concentrations), convert it to mass of cobalt(II) hydroxide and scale down to 500 ml.
AWK

Offline Vidya

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Re: Precipitation in buffer solution
« Reply #2 on: January 18, 2017, 08:00:59 PM »
Start to solve it as advised by AWK
We will help you as you wherever you need help.

Offline Mimic

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Re: Precipitation in buffer solution
« Reply #3 on: January 20, 2017, 08:54:08 AM »

Offline AWK

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Re: Precipitation in buffer solution
« Reply #4 on: January 20, 2017, 09:05:37 AM »
Quote
what is the amount by weight of hydroxide which precipitates?
AWK

Offline Mimic

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Re: Precipitation in buffer solution
« Reply #5 on: January 20, 2017, 02:33:22 PM »

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