Distinguish chemicals

Both Pb(NO3)2 and Zn(NO3)2 are soluble in water to form solutions. However, PbCl2 is insoluble in water, but ZnCl2 is soluble.

Method to distinguish between Pb(NO3)2 and Zn(NO3)2:
Add separately dilute HCl to each of the solutions of Pb(NO3)2­ and Zn(NO3)2.

Observation and equation:
The Pb(NO3)2 solution gives a white precipitate of PbCl2.
Pb2+(aq) + 2Cl-(aq) → PbCl2(s)
or Pb(NO3)2(aq) + 2HCl(aq) → PbCl2(s) + 2HNO3(aq)
The Zn(NO3)2 solution has no observable change, because there is no reaction.
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