January 9, 2013
Partners: Kelsy Shay Katie Nelson
The purposes of this experiment are to separate two components in a mixture, specifically sodium chloride and silica, and find the correlating percent composition of each. Abstract:
This experiment consisted of the separation of sodium chloride and silica. The mixture was separated by extracting the sodium chloride with water and drying both substances. Adding water to the mixture, stirring, then decanting the resulting liquid twice extracts the dissolved sodium chloride from the silica. Heating both sodium chloride and silica separately provides the mass of each. The data from this experiment can be used to calculate the percent composition of sodium chloride and silica when in a mixture. When this experiment was performed, the percent composition of sodium chloride came out to be 47% and 53% of silica.
To start, weigh a dry evaporation dish to 0.01g. Next add 2-3 g of the sodium chloride and silica mixture to the evaporation dish and reweigh to ascertain the exact mass of the mixture. Then distilled water and a glass stirring rod need to be obtained. Using the distilled water, add 15-20 mL to the mixture and mildly stir for about five minutes to dissolve the sodium chloride. Next weigh one more evaporating dish and a watch glass. Then decant the resulting sodium chloride liquid into the second dish, be sure not to transfer any solid along with the liquid. Next add 5 mL of the distilled water again to the first dish, stir and decant this to the second dish again. After this place the watch glass on the second evaporating dish with the sodium chloride solution and gently heat the solution. Do not boil the water to avoid spattering. Once most of the water has been driven off the evaporating dish, reduce the heat slightly. When the sodium chloride is dry and no more water condenses on the watch glass turn off the heat....