Strukturna kemija: Navodila za vaje

Structural Chemistry: Exercise Instructions. The laboratory manual for the Structural Chemistry course describes four experiments focused on crystallization phenomena and the structural characterization of crystalline materials. The first experiment investigates supercooling of water, examining the conditions under which water can remain liquid below its freezing point and the influence of impurities, crystallization nuclei, and prior boiling on nucleation processes. The second experiment studies the crystallization of NaCl in the presence of additives, particularly urea, and evaluates how different additives and their concentrations affect the morphology of NaCl crystals. The third experiment introduces X-ray powder diffraction (XRD) as a method for the qualitative analysis of crystalline materials, with emphasis on proper sample preparation and factors influencing measurement quality. In the fourth experiment, XRD is used to construct a calibration curve for the NaCl–Na₂CO₃ system and to determine the composition of an unknown binary mixture based on diffraction peak intensities.