1 / 9

Qualitative Analysis: Group I

Qualitative Analysis: Group I. General Chemistry 101/102 Laboratory Manual University of North Carolina at Wilmington. Safety Considerations. Pb 2+ and Hg 2 2+ ions are very toxic. Wash your hands thoroughly after this experiment.

abedi
Download Presentation

Qualitative Analysis: Group I

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


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

  2. Safety Considerations • Pb2+ and Hg22+ ions are very toxic. • Wash your hands thoroughly after this experiment. • Place all waste solids and solutions in the appropriately labeled containers in the hood. 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.

  3. General Procedures • Use clean glassware and deionized water to avoid contaminating your sample. • Distinguish between clear, cloudy, colored, and colorless in your descriptions. cloudy yellow clear yellow clear colorless white solid Qualitative Analysis: Group I

  4. Qualitative Analysis: Group I • General Procedures • Exercise caution when using the centrifuge. Use a counterbalance tube. counterbalance sample

  5. General Procedures • Pay attention to whether you are to keep or discard the precipitate and/or supernatant. supernatant precipitate • Use a water bath to heat all mixtures. Qualitative Analysis: Group I

  6. 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

  7. Pb2+ ions can be precipitated with K2CrO4. PbCrO4 is insoluble in hot and cold water. PbCrO4 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.

  8. Ag+ ions can be precipitated as AgCl by the addition of HNO3. 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.

  9. Qualitative Analysis: Group I

More Related