A laboratory experiment based on the determination of density, suitable for introductory-level chemistry courses, is described. Students prepare several aqueous solutions of sugar of known concentration in the 0-15% by mass range. The density of each solution and of commercial beverage samples is measured by weighing a known volume of solution delivered by a volumetric pipet. A graph of density versus sugar concentration is prepared and used to determine the percent by mass of sugar in the beverage samples. The experiment provides students an opportunity to develop skills in weighing, preparing solutions, pipetting, constructing and using a calibration curve, and proper use of significant figures. The materials used in the experiment are inexpensive, do not pose physical or health hazards, and do not result in the production of hazardous waste. The nature of the samples and the purpose of the experiment stimulate students' interest.
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Citation
Henderson, Susan K.; Fenn, Carol A.; Domijan, John D. J. Chem. Educ.1998 75 1122.
Keywords
introductory, high school chem, laboratory instruction
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