There is quite a bit of chemistry involved in these tests. Ammonia, Hydroxy(thio)pyrone and hydroxy(thio)pyridinone

Cu2+(aq) + 4 NH3(aq) à Cu(NH3)42+ (Equation 1)

Ag+(aq) + 2 NH3(aq) à Ag(NH3)2+ (Equation 2)

Fe(s) + Cu2+(aq) à Cu(s) + Fe2+(aq) (Equation 3)

Functions :

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