Introduction of Synthesis of Zinc Iodide Lab Report

Introduction of Synthesis of Zinc Iodide - Lab Report Example The chemical equation (Eqn 1) below presents the synthesis of zinc iodide from its reactants in the presence of water (Sheppard, 1): The technique involved in this experiment is gravimetry, which is defined as the determination of the mass of substances involved in the reaction (â€Å"Gravimetric Analysis†, tamu.edu). Based on the chemical equation, zinc iodide is expected to precipitate from the reaction, and the precipitate is subjected to washing procedure to collect the excess reactants, which are also weighed (Sheppard, 1). Impurities are the unwanted substances in the precipitate and may affect the percent yield of the product obtained which may be brought about by co-precipitation, surface absorption, occlusion and post-precipitation. Surface adsorption happens when impurities present in the mixture are adsorbed during precipitation. Post-precipitation occurs when a different precipitate forms on top of the expected product while in contact with the mother liquor. In the experiment, surface absorption and post-precipitation may likely introduce the impurities in ZnI2, but this can be avoided by thorough washing of the precipitate and careful precipitation during reaction (â€Å"Gravimetric Analysis†, tamu.edu) of zinc and