Lesson 1 : Intro

• Analytical chemistry is the branch of science that deals with the separation, identification and determination of the components in a sample.
• Accuracy in analytical chemistry pertains to agreement of experimental results with true value.
• Modern techniques such as atomic absorption spectroscopy and ICP-MS (Inductively coupled plasma mass spectrometry) are able to quickly detect the presence and concentrations of elements using a very small amount of sample.
• Precision in analytical chemistry is the measure of reproducibility of data within a series of results.
• All non-zero digits are significant in significant figures.
• Qualitative Analysis in analytical chemistry involves identification, composition determination and ascertainment of impurities.
• Quantitative chemistry in analytical chemistry determines the proportion of components in a substance.
• Ultra Microanalysis in analytical chemistry involves samples less than 1 mg.
• Microanalysis in analytical chemistry involves samples between 1 mg and 10 mg.
• Semi-microanalysis in analytical chemistry involves samples between 10 mg and 100 mg.
• Macroanalysis in analytical chemistry involves samples between 100 mg and 1g.
• A sample in analytical chemistry is the substance that is being analyzed and observed.
• A reagent in analytical chemistry is a chemical tool used to analyze.
• Proximate analysis in analytical chemistry determines the total amount of a class or a group of active plant principles in a given sample.
• Ultimate analysis in analytical chemistry determines the amount of a specific constituent or a single chemical species present in the sample.
• Chemical methods in analytical chemistry use titrimetric method.
• Physical methods in analytical chemistry use instruments and special apparata.
• Biological methods in analytical chemistry use microorganisms and animals and parts thereof.
• Physico-Chemical Methods in analysis are based on some specific physical or chemical property or properties of the substance being analyzed with the use of instruments such as: spectrophotometer, chromatograph units, polarographer, polarimeter, flourometer.
• Distillation is a method used in analysis to determine alcohol, protein components, volatile component, alkaloids.
• Moisture Balance is a method used in moisture content.
• AgCl is reduced to silver under light, which gives samples a violet colour.
• The 1st analytical group of cations consists of ions that form insoluble chlorides, separated by hydrochloric acid, usually used at a concentration of 1–2 M.
• Concentrated HCl must not be used, because it forms a soluble complex ion ([PbCl4]2-) with Pb2+, resulting in the Pb2+ ion going undetected.
• Ammonia is used as a reagent to distinguish between the other two.
• Chromatography is a method used in identity and quantity of component.
• PbCl2 is far more soluble than the chlorides of the other two ions, especially in hot water.
• Polarography is a method used in quality and quantity of components.
• The most important cations in 1st group are Ag+, Hg 2+, and Pb2+.
• Polarimeter is a method used in rotatory power.
• AgCl dissolves in ammonia due to the formation of the complex ion [Ag(NH3)2]+, while Hg2Cl2 gives a black precipitate consisting of a mixture of chloro-mercuric amide and elemental mercury.
• Microscopy is a method used in physical characterization.
• Spectroscopy is a method used in identity and purity.
• Biological tests are methods used in determination of amounts required to produce the desired, definite effect.
• The chlorides of 2 of these elements cannot be distinguished from each other by their colour, they are all white solid compounds.
• Refractometer is a method used in purity of substance.
• Pb2+ is usually also included in the 2nd analytical group.
• Analysis involves the accurate measurement of weight of substance being determined which may be isolated in pure form or converted to another substance of known composition by making it react quantitatively with another substance usually a precipitant.
• Qualitative Inorganic Analysis involves detecting cations according to their properties, usually classifying them into five groups.
• Oven is a method used in moisture content.