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bob has the salt solutions in the list below. he does not know which is which.
he has:
-magnesium chloride
-zinc chloride
-copper chloride
bob also has pieces of magnesium, iron, zinc and copper.
explain how bob could use his materials to work out which solution is which

Displcement reaction. metal added to solutions containing metal that is less reactive would have visible reaction while less reactive metal will have no visible reaction. Eg, if copper is added to Mgcl2 andZnCl2, there will be no visible reaction. If Mg is added to CuCl2, blue solution will fade to form colourless solution and a reddish brown ppt of Cu will be formed.