form.4 chem~~

Test for copper(II) ion
Dissolve the solid with hot water, add potasium hexacyanoferrate(II) solution. Brown colour or precipitate due to copper hexacyanoferrate(II) proves presence of copper.
2Cu2+ + [Fe(CN)6]4- --> Cu2Fe(CN)6(s)
Confirmatory test for copper(II) ion
Add ammonia solution gives a pale blue precipitate which dissolves in excess to give a deep blue solution.
Cu2+ + 2 OH- --> Cu(OH)2(s)
Cu(OH)2 + 4 NH3 --> [Cu(NH3)4]2+ + 2 OH-
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Test for chloride radical
Add excess dilute nitric acid, followed by silver nitrate solution. A white curdy precipitate of silver chloride, readily soluble in ammonia solution, proves the presence of chloride radical.
Ag+ + Cl- --> AgCl(s)
AgCl + 2 NH3 --> [Ag(NH3)2]+ + Cl-
　　　　　　　soluble diamminesilver ion
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Test for calcium ion
Add an excess of ammonia solution and ammonium oxalate solution. White precipitate of calcium oxalate proves presence of calcium.
Confirmatory test for calcium ion
Flame test --- Brick-red (light green through blue glass)
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Test for potassium ion
Evapourate the solution and examine the residue by flame test. Lilac flame proves presence of potassium
Confirmatory test for potassium ion
Add sodium perchlorate (chlorate(VII)) solution to equal volume of test solution. White precipate of potassium perchlorate shows potassium.
I hope this can help your understanding. =)