Qualitative Analysis: Group I

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Qualitative Analysis Group I
General Chemistry 101/102Laboratory
ManualUniversity of North Carolina at Wilmington
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Qualitative Analysis Group I

• Purpose

• To study the chemical properties of Ag, Pb2,
  and Hg22 ions and the compounds they form.
• Use the chemical properties of these ions to
  identify their presence in an unknown mixture.

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Qualitative Analysis Group I
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Qualitative Analysis Group I

• General Procedures

• Exercise caution when using the centrifuge. Use a
  counterbalance tube.

counterbalance
sample
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Qualitative Analysis Group I
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Qualitative Analysis Group I

• Background

• Ag, Pb2, and Hg22 ions all form white
  precipitates with Cl - at room temperature.

6 M HCl
AgCl, PbCl2, Hg2Cl2
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Qualitative Analysis Group I

• Background

• PbCl2 is insoluble in cold water but soluble in
  hot water. PbCl2 can be separated from AgCl and
  Hg2Cl2 by heating the mixture.

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Qualitative Analysis Group I

• Background

• When NH3(aq) is added to a mixture of AgCl and
  Hg2Cl2, the AgCl dissolves and a gray-black
  mixture of Hg and HgNH2Cl is formed.

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Qualitative Analysis Group I