The objective of the first lab is to use the graph of Pressure versus Temperature to estimate the value of Absolute Zero. Based on the Gay-Lussac’s Law, pressure is proportional to temperature; we are able to find the Absolute Zero when the pressure reaches zero.
Our experimental result is -285.40 C. It means when pressure reaches zero, the temperature should reach -273.15 C, which is the value of Absolute Zero. Our experimental Absolute Zero value is fairly close to the accepted value, and the percentage error is 4.48%. One of the major sources of error in this experiment is that the volume of metal ball will rise while the surrounding water’s temperature rise. The metal ball has fixed amount of gas, so with higher volume the inner pressure of the metal ball will be lower. In order to reduce the error and improve this experiment, we can use a metal with lower coefficient of volume expansion.
The objective of the second lab is to determine the relationship between the pressure and volume of gas with fixed temperature. Based on the Bayle’s Law, the pressure of the gas is inversely proportional to the volume with fixed temperature.
Our experimental result shows the slope of our graph of Inverse Volume versus Pressure is 2330 + 15Kpa*ml. We used the slope divided by (R*T), then we are able to find value of n which is n=9.50*10^-4. Our graph is a linear line, which means the product of pressure and volume is a constant (value of slope). Thus we are able to find that the pressure of gas is inversely proportional to the volume with fixed temperature. One of the major sources in this experiment is that the contact of human body to the syringe will raise the temperature of syringe, thus the pressure will be higher. We can use some mechanical device to adjust the volume of air in the syringe. It will help to prevent the human body contact, thus to avoid error and improve the experiment.