Gay-Lussac’s Law Lab: Analyzing the Relationship Between Temperature and Pressure in Gases Ethan Cossu – 6th Period Date of Experiment: 3/22/18 Lab Partners: Isabella Miramontes, Anthony Stross, and Karoline Tyrell Purpose: The purpose of this experiment was to analyze and determine the relationship between the temperature of a gas and the resulting pressure. Procedure: We followed the directions and steps that were provided in the lab. In summary, my lab partners and I placed a 125-mL Erlenmeyer flask, containing an air sample, into water baths of varying temperature. Pressure was monitored with the Vernier Gas Pressure Sensor and temperature was monitored with the Vernier Temperature Probe. The volume of the gas and the number of molecules it contained was assumed to be kept constant. Data: Pressure (kPa) Temperature (C°) Temperature (K) Constant, k (P/T) 1. 93.97 3.4 276.4 0.340 2. 101.49 23.7 296.7 0.342 3. 112.27 53.7 326.7 0.344 4. 115.27 71.2 344.2 0.335 Question 6 Graph Calculations Pressure (kPa) Temperature (C°) Temperature (K ) (C° + 273) Constant, k k= 𝑝𝑟𝑒𝑠𝑠𝑢𝑟𝑒 𝑡𝑒𝑚𝑝𝑒𝑟𝑎𝑡𝑢𝑟𝑒 1. 93.97 3.4 3.4 + 273 = 276.4 93.97/276.4 = 0.340 2. 101.49 23.7 23.7 + 273 = 296.7 101.49/296.7 = 0.342 3. 112.27 53.7 53.7 + 273 = 326.7 112.27/326.7 = 0.344 4. 115.27 71.2 71.2 + 273 = 344.2 115.27/344.2 = 0.335 Uncertainty/Error Analysis: During the experiment, it could have been plausible that gas escaped the flask or liquid entered it when placing it in each water bath. It is also possible that my lab group and I failed to submerge the flask for a sufficient amount of time. Discussion and Conclusion: Based on the graph and data table, my lab partners and I observed a strong, positive linear relationship between the pressure and temperature of a gas. This means that as the temperature increases, pressure increases. As we placed the flask in hotter temperatures, the pressure subsequently increased. On the contrary, after placing the flask in the colder ice bath, we observed that the pressure, along with the temperature, decreased. These conclusions are in perfect alignment with Gay-Lussac’s Law, stating that the pressure-temperature correlation in a gas is a direct relationship. Questions: 1. In order to perform this experiment, the two experimental factors that were kept constant were the volume of the gas and the amount of gas in the flask. 2. Based on the graph and table that I obtained for this experiment, the relationship between temperature and pressure of a gas is one in which the pressure will vary DIRECTLY with the temperature. If temperature increases, so does pressure, a direct relationship. 3. Using the concepts of molecular velocity and collisions of molecules, the increase in temperature would allow the molecules to move at a faster rate. The fastmoving molecules will have more collisions thus increasing the pressure. 4. Write an equation to express the relationship between pressure and temperature (K). Use the symbols P, T, and k. 𝐶𝑜𝑛𝑠𝑡𝑎𝑛𝑡 = 𝑝𝑟𝑒𝑠𝑠𝑢𝑟𝑒 𝑡𝑒𝑚𝑝𝑒𝑟𝑎𝑡𝑢𝑟𝑒 𝐾= 𝑃 𝑇 5. The relationship is direct; thus, we used the formula above. Our values were relatively constant with one minor change in the last trial in which the constant decreased slightly. See data table and calculations. 6. Utilizing the techniques of this experiment, if the Kelvin temperature is doubled, so will the pressure. The pressure at 200 K is about 74 kPa. The pressure at 400 K is about 148 kPa. The second pressure is double the first. See graph in data.