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chem group 2 alevel aqa

Which one of the following is a correct procedure for isolating a sample of hydrated copper(II) sulphate from a mixture of hydrated copper(II) sulphate and barium sulphate?
A filter, crystallise filtrate, dry the crystals
B filter, dry the solid on the filter paper
C add water, filter, dry the solid left on the filter paper
D add water, filter, crystallise filtrate, dry the crystals

how do u do this and where is this in the spec i can't seem to find it
Original post by ricecakes1
Which one of the following is a correct procedure for isolating a sample of hydrated copper(II) sulphate from a mixture of hydrated copper(II) sulphate and barium sulphate?
A filter, crystallise filtrate, dry the crystals
B filter, dry the solid on the filter paper
C add water, filter, dry the solid left on the filter paper
D add water, filter, crystallise filtrate, dry the crystals
how do u do this and where is this in the spec i can't seem to find it

It's a question about separating techniques, although it is synoptic in that it brings in tests for salts (sort of).
You should know that filtration cannot separate solids, so A & B are out.
Then you should know that barium nitrate (or chloride) is used to test for the presence of sulfates by forming an insoluble precipitate of barium sulfate. Hence, barium sulfate does not dissolve.
So the copper sulfate dissolves in the water and the barium sulfate can be filtered off.
To obtain copper sulfate crystals from the solution you must crystallise and dry them.
D
Reply 2
Original post by charco
It's a question about separating techniques, although it is synoptic in that it brings in tests for salts (sort of).
You should know that filtration cannot separate solids, so A & B are out.
Then you should know that barium nitrate (or chloride) is used to test for the presence of sulfates by forming an insoluble precipitate of barium sulfate. Hence, barium sulfate does not dissolve.
So the copper sulfate dissolves in the water and the barium sulfate can be filtered off.
To obtain copper sulfate crystals from the solution you must crystallise and dry them.
D

thank u so much

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