Qualitative Analysis Lab Report

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Quantitative analysis is the determination of an amount present in a variety of settings. On the other hand, qualitative analysis is the determination of non-numerical information about a reaction, such as observing that a reaction results in a color change. There are chemical changes that separate cations and physical separations, such as decanting, where liquid is poured from a solid-liquid mixture, leaving the solid behind. Centrifuging is another separation technique, where a solid is separated from a liquid by whirling the mixture at high speed. A mixture of metal ions in a solution can be separated by a reaction of precipitation and in this experiment, the metal cations of aluminum, nickel, and iron ions will be separated from a solution…show more content…
The cations in both the known and unknown samples were identified by using qualitative analysis, of which were determined to be acidic, basic, or neutral by using litmus paper. Acid-base reactions, oxidation-reduction reactions, and the formation of complex ions are often used in a systematic way for either separating ions or for determining the presence of specific ions. When white precipitate formed after adding hydroxide, aluminum ion was determined to be present in the solution. However, nickel was determined to test positive when the solution changed to a hot pink color after adding a few drops of dimethylglyoxime reagent and iron was present when the solution was a reddish brown color when sodium hydroxide was added to the mixture at the very beginning of the experiment. Qualitative analysis determines that ions will undergo specific chemical reactions with certain reagents to yield observable products to detect the presence of specific ions in an aqueous solution where precipitation reactions play a major role. The qualitative analysis of ions in a mixture must add reagents that exploit the more general properties of ions to separate major groups of ions, separate major groups into subgroups with reactions that will distinguish less general properties, and add reagents that will specifically confirm the presence of individual
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