Chemistry · Ch 2 — Introduction to Analytical Chemistry
Analysis
Analysis
Analysis is always carried out on a small, carefully chosen sample of the material being tested, never on the entire bulk of it, because testing the whole bulk would usually destroy or consume the material and is rarely practical. When only a few grams of a solid or liquid sample are used, the procedure is called semi-microanalysis. Like analysis in general, semi-microanalysis is of two types, qualitative and quantitative. Classical qualitative analysis relies on separation techniques such as precipitation, extraction and distillation to isolate a substance, and then identifies it from physical differences such as colour, odour, melting point, boiling point and chemical reactivity. Classical quantitative analysis, by contrast, relies on methods such as volumetric analysis (measuring the volume of a reagent solution needed to complete a reaction) and gravimetric analysis (measuring the mass of a product formed or isolated) to arrive at a numer …
Worked out. The textbook highlights this definition in a boxed 'Remember' note: analytical chemistry is the branch of chemistry that deals with the study of separation, identification, and qualitative and quantitative determination of the composition of different substances. The box also explains why the subject matters in practice: the course of analytical chemistry extends the knowledge students already have from general, inorganic and organic chemistry into a working skill. Chemical analysis is one of the most important tools for monitoring the composition of raw materials, intermediates and finished products in industry, and also for monitoring the composition of air in streets and inside industrial premises. In agriculture, chemical analysis determines the composition of soils and fertilizers; in medicine, it determines the composition of medicinal preparations. Analytical chemistry also finds applications in forensic science and engineering, and is closely tied to industrial process control and the development o …