Introduction to Analytical Chemistry Exam Questions with Verified Answers Rated A+ (Already Passed)

Introduction to Analytical Chemistry Exam Questions with Verified Answers Rated A+ (Already Passed) love - Answers shaira renz - Answers shai often called the central science; its top center position and the central position of analytical chemistry. - Answers Chemistry is a measurement science consisting of a set of powerful ideas and methods that are useful in all fields of science, engineering, and medicine. - Answers Analytical chemistry must be able to design, carry out, and interpret measurements within the context of the fundamental technological problem with which he or she is presented. - Answers analyst The selection and utilization of suitable chemical procedures requires a ? - Answers wide knowledge of chemistry while familiarity with and the ability to operate a varied range of instruments is? - Answers is essential must have a sound knowledge of the statistical treatment of experimental data to enable them to gauge the meaning and reliability of the results that they obtain - Answers analysts reveals the identity of the constituents (elements and compounds) in a sample. - Answers Qualitative analysis indicates the amount of each substance in a sample. - Answers Quantitative analysis the components of a sample that are determined either through qualitative or quantitative analysis. - Answers Analytes common between the techniques and methods used in qualitative and quantitative analysis. - Answers In both cases, a sample is prepared for analysis by physical and chemical 'conditioning', and then a measurement of some property related to the analyte is made. major difference of qualitative and quantitative lies? - Answers It is in the degree of control over the relation between a measurement and the amount of analyte present For a ___________ it is sufficient to be able to apply a test which has a known sensitivity limit so that negative and positive results may be seen in the right perspective. - Answers qualitative analysis Where a ______________ is made, however, the relation between measurement and analyte must obey a strict and measurable proportionality; only then can the amount of analyte in the sample be derived from the measurement. - Answers quantitative analysis To maintain this proportionality, it is generally essential that all reactions used in the preparation of a sample for measurement are ______ and ________ and that the conditions of measurement remain constant for all similar measurements. - Answers controlled, reproducible A _______ is also placed upon careful calibration of the methods used in a quantitative analysis. - Answers premium These aspects of chemical analysis are a major pre-occupation of the analyst. - Answers 6 Functions of Analytical Chemistry - Answers Fundamental Research Product Development Product Quality Control Monitoring and Control of Pollutants Assay Medical and Clinical Studies The first steps in unravelling the details of an unknown system frequently involve the identification of its constituents by qualitative chemical analysis. Follow-up investigations usually require structural information and quantitative measurements. This pattern appears in such diverse areas as the formulation of new drugs, the examination of meteorites, and studies on the results of heavy ion bombardment by nuclear physicists. - Answers Fundamental Research The design and development of a new product will often depend upon establishing a link between its chemical composition and its physical properties or performance. Typical examples are the development of alloys and of polymer composites - Answers Product Development Most manufacturing industries require a uniform product quality. To ensure that this requirement is met, both raw materials and finished products are subjected to extensive chemical analysis. On the one hand, the necessary constituents must be kept at the optimum levels, while on the other impurities such as poisons in foodstuffs must be kept below the maximum allowed by law. - Answers Product Quality Control - Residual heavy metals and organo-chlorine pesticides represent two well-known pollution problems. Sensitive and accurate analysis is required to enable the distribution and level of a pollutant in the environment to be assessed and routine chemical analysis is important in the control of industrial effluents. - Answers Monitoring and Control of Pollutants - In commercial dealings with raw materials such as ores, the value of the ore is set by its metal content. Large amounts of material are often involved, so that taken overall small differences in concentration can be of considerable commercial significance. Accurate and reliable chemical analysis is thus essential. - Answers Assay - The levels of various elements and compounds in body fluids are important indicators of physiological disorders. A high sugar content in urine indicating a diabetic condition and lead in blood are probably the most well-known examples. - Answers Medical and Clinical Studies Definition of Terms - Answers Definition of Terms - The closeness of an experimental measurement or result to the true or accepted value - Answers Accuracy - Constituent of the sample which is to be studied by quantitative measurements or identified qualitatively. - Answers Analyte - A highly accurate determination, usually of a valuable constituent in a material of large bulk, e.g. minerals and ores. Also used in the assessment of the purity of a material, e.g. the physiologically active constituent of a pharmaceutical product. - Answers Assay - That proportion of a measurement which arises from sources other than the analyte itself. Individual contributions from instrumental sources, added reagents and the matrix can, if desired, be evaluated separately. - Answers Background A measurement or observation in which the sample is replaced by a simulated matrix, the conditions otherwise being identical to those under which a sample would be analyzed. Thus, the blank can be used to correct for background effects and to take account of analyte other than that present in the sample which may be introduced during the analysis, e.g. from reagents. - Answers black - (1) A procedure which enables the response of an instrument to be related to the mass, volume or concentration of an analyte in a sample by first measuring the response from a sample of known composition or from a known amount of the analyte, i.e. a standard. - Answers Calibration Often, a I of standards is used to prepare a calibration curve in which instrument response is plotted as a function of mass, volume or concentration of the analyte over a given range. If the plot is linear, a calibration factor (related to the slope of the curve) may be calculated. This facilitates the rapid 1computation of results without reference to the original curve. (2) Determination of the accuracy of graduation marks on volumetric apparatus by weighing measured volumes of water, or determinations of the accuracy of weights by comparison with weights whose value is known with a high degree of accuracy - Answers calibration