Chem 16 Final Paper
Abstract
Qualitative analysis, a branch of analytical chemistry, deals with the identity of a substance found in a given sample, and not the amount of substance in it. It only concerns the substances present or absent in a given sample. Qualitative analysis is therefore used to determine unknown ions present in chemical samples by observing and analyzing results from various reactions of the sample with chemicals.
Qualitative analysis is done through a series of steps. It is usually divided into two parts, namely: the preliminary and confirmatory tests. Preliminary tests are done to eliminate ion choices, while confirmatory tests are done to confirm the actual ions present in the sample.
Qualitative analysis was done to identify the ions present in a given unknown solution. In this experiment, the qualitative traits of chemicals and their corresponding chemical reactions with other chemicals were more evident and familiar. Five preliminary tests were used to infer possible ions: two for cations, namely, precipitation reactions with hydroxide (OH-) and ammonia (NH3) respectively; and two for anions, namely, precipitation reactions with barium nitrate (Ba(NO3)2), and non-precipitation reactions involving ferric chloride (FeCl3) and potassium permanganate (KMnO4) respectively. Confirmatory tests for all possible ions were also used to confirm the suspected ions from the preliminary tests. The experimentation was repeated thrice. Observed changes were recorded and compared to controlled results from previous studies.
Results of the preliminary and confirmatory tests have shown that the solution contained calcium (Ca2+), ammonium (NH4+) and thiocyanate (SCN-) in all replications.
Keywords: unknown analysis, cations, anions, calcium, ammonium, thiocyanate, preliminary tests, confirmatory tests
Introduction
Analytical chemistry has two divisions, namely: qualitative analysis and quantitative analysis. Qualitative analysis concerns the identity of
Qualitative analysis, a branch of analytical chemistry, deals with the identity of a substance found in a given sample, and not the amount of substance in it. It only concerns the substances present or absent in a given sample. Qualitative analysis is therefore used to determine unknown ions present in chemical samples by observing and analyzing results from various reactions of the sample with chemicals.
Qualitative analysis is done through a series of steps. It is usually divided into two parts, namely: the preliminary and confirmatory tests. Preliminary tests are done to eliminate ion choices, while confirmatory tests are done to confirm the actual ions present in the sample.
Qualitative analysis was done to identify the ions present in a given unknown solution. In this experiment, the qualitative traits of chemicals and their corresponding chemical reactions with other chemicals were more evident and familiar. Five preliminary tests were used to infer possible ions: two for cations, namely, precipitation reactions with hydroxide (OH-) and ammonia (NH3) respectively; and two for anions, namely, precipitation reactions with barium nitrate (Ba(NO3)2), and non-precipitation reactions involving ferric chloride (FeCl3) and potassium permanganate (KMnO4) respectively. Confirmatory tests for all possible ions were also used to confirm the suspected ions from the preliminary tests. The experimentation was repeated thrice. Observed changes were recorded and compared to controlled results from previous studies.
Results of the preliminary and confirmatory tests have shown that the solution contained calcium (Ca2+), ammonium (NH4+) and thiocyanate (SCN-) in all replications.
Keywords: unknown analysis, cations, anions, calcium, ammonium, thiocyanate, preliminary tests, confirmatory tests
Introduction
Analytical chemistry has two divisions, namely: qualitative analysis and quantitative analysis. Qualitative analysis concerns the identity of
References: Larson, L. (2008). Introduction to Qualitative Analysis. Retrieved August 27, 2012 from http://www.foothill.edu/attach/psme/sinha.QualDiscussion.pdf. UP Chemistry Alumni Foundation. (2006). General Chemistry Laboratory Manual. 5th ed. p. 51-55.