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describe how you would distinguish between iron (ii) sulphate, copper iodide and calcium carbonate

i'm really not sure how to approach this question- is it something to with testing for these chemicals present?
Reply 1
Avatar for Pigster
Pigster
20
Original post by entertainmyfaith
describe how you would distinguish between iron (ii) sulphate, copper iodide and calcium carbonate

i'm really not sure how to approach this question- is it something to with testing for these chemicals present?


If you have done test tube reactions of positive or negative ions (e.g. adding sodium hydroxide, silver nitrate, barium chloride/nitrate, acid etc.) then you should be able to do it.
Original post by Pigster
If you have done test tube reactions of positive or negative ions (e.g. adding sodium hydroxide, silver nitrate, barium chloride/nitrate, acid etc.) then you should be able to do it.


i'm a bit confused as we haven't tested for copper iodide but silver iodide- i presume the same rule doesn't apply to it eg. iodide gives a yellow precipitate of silver iodide so it wouldn't be the same for copper iodide
Reply 3
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Pigster
20
Original post by entertainmyfaith
i'm a bit confused as we haven't tested for copper iodide but silver iodide- i presume the same rule doesn't apply to it eg. iodide gives a yellow precipitate of silver iodide so it wouldn't be the same for copper iodide


I guess the plan is to get you to test for the iodide ion by the additional of silver ions, producing the yellow AgI ppt. The metal ion shouldn't matter as you are testing for the iodide ion, rather than for the metal ion.

BUT, CuI is insoluble, so you would get no reaction. My guess is that either the person setting the problem didn't think it through, or set a really rather tricky problem, for which, the only answer I can think of is to do a flame test and look for the distinctive colour of copper(I) ions.
Original post by Pigster
I guess the plan is to get you to test for the iodide ion by the additional of silver ions, producing the yellow AgI ppt. The metal ion shouldn't matter as you are testing for the iodide ion, rather than for the metal ion.

BUT, CuI is insoluble, so you would get no reaction. My guess is that either the person setting the problem didn't think it through, or set a really rather tricky problem, for which, the only answer I can think of is to do a flame test and look for the distinctive colour of copper(I) ions.


... "the distinctive colour of copper(I) ions"?
Reply 5
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Pigster
20
Original post by charco
... "the distinctive colour of copper(I) ions"?


You like my irony?
Original post by Pigster
You like my irony?


You can do my shirts any day ...

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