Name: Nhung Ly Date: 05/05/2018
Group I Cations
Qualitative analysis is a branch of analytical chemistry that deals with the separation and identification of the components of matter - what is present, not how much is present. There are many common qualitative analysis schemes that separate the ions into groups based on selective precipitation. Although sophisticated instrumental techniques have replaced much of the traditional wet chemistry analytical methods, qualitative analysis remains an important part of the laboratory experience in general chemistry. In qualitative analysis, the ions in a mixture are separated by selective precipitation. Selective precipitation involves the addition of a carefully selected reagent to an aqueous mixture of ions, resulting in the precipitation of one or more of the ions, while leaving the rest in solution. Once each ion is isolated, its identity can be confirmed by using a chemical reaction specific to that ion. It is important to learn this analysis to know the ions involved in an unknown sample. It helps to solve some environmental problems such as contamination of unknown ions in a body of water, contamination of a toxic chemical in foods, etc.
Introduction. Part A:
The purpose of this laboratory was to follow a classic analytical scheme to separate and identify the ions in an unknown mixture of group I cations, and then apply this scheme to identify the ions in an unknown mixture of group I cations.
Introduction. Part B. Underlying Scientific Theory:
In this experiment we will analyze a solution containing Ag+, Pb2+ and Hg22+. This mixture will be analyzed by separating the two ions, and then confirming the presence of each. By keeping detailed observations for the known analysis, you will then be able to identify an unknown solution containing one or both ions by carrying out the same procedure you did for the knowns and comparing the observations you collected for the unknown with those of the known.
Experimental Details, Computation Procedures, and results:
First, mix equal volumes of ....