GC Quesiton

[hope_to_match]

Advertisement - Members don't see this ad

I was debating between these two answers and ended choosing the wrong one. I understand the explanation and it makes sense that it all depends on concentrations etc...but the reason I didn't choose answer D is because not all salts are soluble in water. So wouldn't that answer also have to depend on what kind of salt we are talking about here?

 

[FeralisExtremum]

Keep in mind that the question already tells you that this hypothetical is taking place in a solution that already has the dissolved ions/salt in question. They also specifically say dissolve, which implies that insolubility is not an issue.

 

[hope_to_match]

Keep in mind that the question already tells you that this hypothetical is taking place in a solution that already has the dissolved ions/salt in question.

yes that's why I figured that if we add more of the same ion the equilibrium will shift to the left, hence it will precipitate. isnt this the common ion effect? how can we make an assumption that it will be less soluble than in water if we don't know the identity of the salt, so how can we compare this hypothetical solution that the salt is already dissolved in to it's solubility in water?


or when it says "solution" we should assume it's water?

 

[FeralisExtremum]

Common ion effect tells us that if an ion is already dissolved in solution, the solubility of a salt containing that ion will be reduced. Eventually it would precipitate out, but that is dependent on unspecified things like amount added and concentration, which is beyond the scope of the question.

D is a better answer than B because D is always true, whereas B is only true if certain conditions are met.

 

[hope_to_match]

Common ion effect tells us that if an ion is already dissolved in solution, the solubility of a salt containing that ion will be reduced. Eventually it would precipitate out, but that is dependent on unspecified things like amount added and concentration, which is beyond the scope of the question.

D is a better answer than B because D is always true, whereas B is only true if certain conditions are met.

ok thank you or clarification. i think this was a tricky question for me...