just a few chemistry questions?

Question

a) Explain what is meant by a positive ion test.
B) Describe two types of cahnges that demonstrate a positive test.


2. Suposse that you were asked to determine whether an ion was present in a soulution and how much ion was present

a)Compare amounts of the precipitate that you would expect if you added barium cholorise to two solutions that contained different amounts of sulfate ion.

B) Compare the color intensity that you woule expect if you added potassium thiocynate to two solutions that contained different amounts of iron (III) ion.

Answer 1

A test for a positive ion is one which will identify one positive ion by the addition of just one chemical. The usual chemical added is NaOH. There is quite often a precipitate, and that precipitate sometimes has a distinctive colour.

The more sulphate ion present, the more BaSO4 (white) precipitate you will get.

The more Fe3+ ions there are, the deeper red the solution will turn.