Introduction of Synthesis of Zinc Iodide - Lab Report Example

Your Full Your Experiment 4: Synthesis of Zinc Iodide Introduction The reaction of two or more reagents, elementalor as compounds, given the right atmospheric and physical conditions is commonly known as chemical synthesis, and is governed by the Law of Conservation of Mass. This law was proven by Antoine Lavoisier (1743 – 1794), and stated that matter can go through any physical or chemical reaction, but the total mass of the reactants and the products will remain equal (Rogers et al., wisc.edu). The experiment aims to illustrate the Law of Conservation of Mass by reacting zinc metal and iodine to synthesize zinc iodide.

The chemical equation (Eqn 1) below presents the synthesis of zinc iodide from its reactants in the presence of water (Sheppard, 1):Zn(s) + I2(s) → ZnI2(s) Eqn 1 The technique involved in this experiment is gravimetry, which is defined as the determination of the mass of substances involved in the reaction (“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 (“Gravimetric Analysis”, tamu.edu) of zinc and iodine.

Works Cited“Gravimetric Analysis”. tamu.edu. n.p., n.d. Web. 05 Mar 2013.Sheppard. Experiment 4: Synthesis of Zinc Iodide. 2012. Print. Rogers, E., Stovall, I., Jones, L., Chabay, R., Kean, E., and Smith, S. “The Law of Conservation of Mass” in Fundamentals of Chemistry. chem..wisc.edu. Falcon Software Inc., 2000. Web. 05 Mar 2013