Unknown Gas Identification

690 Words3 Pages
Procedures Identifying the Volume of Each Flask Each flask was filled with distilled water to find so that the true volume of the flask, when filled beyond its measurement marks, could be attained. The true of volume of each flask was found to be slightly greater than 250 ml. The first flask, as well as the third, contained a total volume of 250 ml. The second flask had a volume of 252 ml. Calculating the Weight of Each Flask The mass of each flask with its corresponding stopper was measured while the flasks were filled with only air. The first flask weighed 166.646 grams; the second, 138.536 grams; and the third, 137.230 grams. Using the measurements acquired for each flask, the ideal gas law was used to calculate the mass of the flasks alone. Without the weight of the air, masses of the flasks decreased to 166.343 grams, 138.230 grams, and 136.927 grams, respectively. Determining the Mass and Flammability of Each Unknown Gas Once the true mass of each flask was determined, the three flasks were each filled with one unknown gas. The flasks were weighed next. As a result of subtracting the mass of the empty flask from the mass of the gas-filled vessels, the number of grams of gas each container held was found. Once this was accomplished, the flammability of each gas was tested in order to provide more accurate evidence for the identity of each unknown substance. RESULTS The first flask held .305 grams; the second, .454 grams; and the third, .477 grams of unknown gas. According to the ideal gas law, at a pressure of 762.0 mmHg and 16.0ºC, a vessel of 250 ml will contain .0105 moles of gas, while a vessel of 252 ml will contain .0106 moles of gas. Dividing the number of grams of unknown gas contained in each flask by the corresponding number of moles contained in that vessel resulted in a molar mass for each of the flasks. The
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