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Dat Destroyer General Chem number 37 -soluble in NH3 - REALLY confused

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Mrhyde

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37) Which of the following compounds would be most soluble in NH3? Etc...

---- I am super confused with this question :-(

- So none of the solubility rules apply since this is not in water but in NH3 ??

-- and when the explanation says that transition metals have a tendency to form complex ions, does that only apply to NH3? I want to understand what this applies to so i can learn it.

---And I dont get the explanation since its basically saying that forming complex ions means that its soluble ? But that's not right because something being soluble mean it dissociates and thus does not form a precipitate so how does forming complex ions apply to that ?
 

Alikhan9

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Transitional complex forms with transition metal, I guess that threw me off to that question
 

DAT Destroyer

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37) Which of the following compounds would be most soluble in NH3? Etc...

---- I am super confused with this question :-(

- So none of the solubility rules apply since this is not in water but in NH3 ??

-- and when the explanation says that transition metals have a tendency to form complex ions, does that only apply to NH3? I want to understand what this applies to so i can learn it.

---And I dont get the explanation since its basically saying that forming complex ions means that its soluble ? But that's not right because something being soluble mean it dissociates and thus does not form a precipitate so how does forming complex ions apply to that ?
Ammonia can react with many Transition metals to form complex ions. These reactions involve the NH3 emptying electrons into the d orbitals of many transition metals. Essentially, Ammonia will remove these ions......For example...if FeCl3 is dissolved in water....it is not very soluble. We would get a few Fe+3 ions and a few Cl- ions.......BUT in NH3....we would be REMOVING the Fe+3 ions to from a complex with ammonia...thus....by Le Chatelier's Principle...more of the FeCl3 would dissolve to replace the Fe+3 ions removed by the ammonia. Ammonia can form Complex ions....so can molecules like CN-, and OH-...but for the DAT exam.....only focus on NH3.

Hope this helps.

Dr. Romano
 
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