Objective: In this lab, students learned the different methods there is to separate substances from one another. They practiced the process of decantation, extraction, filtration, and sublimation. Introduction: Theory: Before being able to isolate the components in a mixture, the students should’ve become familiar with the physical properties of each of the substances. The students were given an unknown sample which has a combination of three different components. These components include: NaCl, NH₄Cl, and SiO₂. Because NH₄Cl has a boiling point of 520℃, it can be extracted from the mixture by heating up (sublimating) the substance. Similarly, because NaCl is water soluble while SiO₂ is not, the separation of these two can be done by the …show more content…
When actually given the original sample, we recorded the mass of the evaporating dish with the original sample. Once having calculated the mass of the original sample, we placed the dish with the mixture on a heating plate to allow NH₄Cl to sublimate into fumes under the fume hood. After the fumes deceased and the evaporating dish cooled down to room temperature, we recorded the mass of the dish without the component of NH₄Cl. Next, we slowly added 25 mL of water into the evaporating dish with the remaining components. We then stirred the substance until the NaCl was completely dissolved into the water. After waiting a few minutes to allow the SiO₂ to sit, we carefully poured out the water carrying NaCl into another evaporating dish; keeping only the SiO₂ in the original dish. This process is known as decantation. My partner and I then proceeded to place both evaporating dishes on a heating plate to evaporate the remaining water from the NaCl and to dry the SiO₂. Once both substances were dry, we waited for the two dishes to cool and measured the individual mass of the NaCl and