Separation Of Substances: Sublimation, Extraction, Sub

Purpose
This experiment deals with separating substances. The objective was to become familiar with the methods of separating substances from one another using decantation, extraction, sublimation techniques.
Brief Introduction This experiment was set to teach research students different methods of separating substances from one another. Materials that are not uniform in composition are set to be impure or heterogeneous and are called mixtures. The separation of the components of mixtures is based upon the fact that each component has different physical properties. The components of mixtures are always pure substances, either compounds or elements, and each pure substance possesses a unique set of properties. Every crystal of a pure substance
Brief Procedure and Any Modifications
Weigh an empty evaporating dish to the nearest 0.001 g using a triple beam balance. Obtain 2-3 g of unknown substance from the instructor. Set up an improvised fume hood consisting of an aspirator, cork, test tubing, and funnel to capture the NH4Cl fumes during the sublimation process. Place the unknown substance in the evaporating dish, and then weigh it. Place the evaporating dish on wire gauze on the iron ring stand. Light the Bunsen burner and adapt it until there is a darker inner flame inside the lighter outer flame. Place the Bunsen burner underneath the improvised fume hood. Heat the evaporating dish for 15 minutes (or until the white fumes disappear). Carefully shake the evaporating dish during the sublimation process. Let the evaporation dish cool. Weigh the dish. Perform the appropriate calculations to
The oils on one’s hands could have altered the masses of this equipment due to the accurate, precise nature of the balance. During the sublimation of NH4Cl from the mixture, white fumes were produced. The improvised fume hood transported the white fumes away from the work area. In this process, the solid NH4Cl changed into a gaseous state and then later on back into a solid again. As the distilled water was added to the NaCl and SiO2 mixture, the soluble NaCl dissolved in the water, allowing these two components to be separated through decantation. The water containing the dissolved NaCl was decanted from the solid SiO2, but it was extremely difficult to remove all drops of water from the evaporating dish containing the SiO2 in order to completely separate these two components. In this lab, the starting point was a mixture of NH4Cl (Ammonium chloride), NaCl (sodium chloride), and SiO2 (sand). Each of these substances retained its own chemical identity throughout the course of this lab. NH4Cl and NaCl are ionic compounds, in which normally a metal bonds to a nonmetal, based on the charges of the ions. SiO2 is a binary molecular compound, which is a combination of two nonmetals that is named using Greek prefixes to clarify the number of each type of atom in the compound. In this lab, the components of the mixture were separated by physical means, and consequently the components underwent