Qualitative Analysis of Cations Overview Getting Started Techniques Procedure FAQ Full Lab Manual Introduction & Goals Chemistry & Background Key Questions Prelab Problems Safety Procedure In Your Write-up Experiments Index ChemLab Home		Goals In this experiment, you will use qualitative analysis to identify the cations in known and unknown samples. By observing the reactions of known cation samples, you will construct a logical flow chart for identifying the components of a mixture of unknown cations. This experiment also illustrates a practical application for the theory of solubility equilibria, a topic covered later on in Chem 3 and 5. To Learn or Review Writing Balanced Chemical Equations Zumdahl, pp. 66-70 Ions and Ionic Compounds Zumdahl, pp. 29-32,36-39 Nature of Dissolved Species Zumdahl, pp. 89-91 Balancing Redox Reactions Zumdahl, pp. 123-129 Introduction to Solubility Equilibria and Ksp Zumdahl, pp. 316-322 Precipitation Reactions Zumdahl, pp. 101-112 pH and Solubility Zumdahl, pp. 323-324 Sulfide Precipitation Zumdahl, pp. 326-327 Qualitative Analysis of Cations Zumdahl, pp. 327-328 Introduction Chemical analysis can be divided into qualitative and the quantitative methods. Quantitative analysis seeks to answer questions like "What is the concentration of my acid solution?" or "What is the percentage of calcium in my marble sample?". Experiments using the techniques of quantitative analysis must be performed carefully, with the goal of determining the result as accurately as possible. Qualitative analysis, on the other hand, answers questions like "Does chalk contain carbonate ion or sulfate ion?" or this experiment's question "What cations are present in my unknown sample?". Although your goal is identification, rather than quantitation, experiments still must be performed with meticulous care. You must make careful observations, keep a careful record in your notebook, and perform all laboratory operations correctly. If your technique is sloppy, your cation identification is likely to be ambiguous or in error. Qualitative analysis makes it possible to separate and identify two or more cations in solution. Most scientific libraries include textbooks on qualitative analysis. We recommend that you leaf through one or more of the qualitative analysis textbooks available in Kresge Library. Note, in general, how common cations can be separated into groups, and study the diagrammatic summaries of the separation and identification of the members of the groups to learn some of the general methods used for analysis and separation.
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