The purpose of this experiment was to understand Boyle's Law. In the experiment the pressure in the system under constant temperature and mass was used to confirm if the laws are true. Boyles law relates pressure and volume while all other factors are consistent and states: for a fixed amount of gas kept at constant temp, the product of the pressure of the gas and its volume will remain constant if either quantity is changed, or where k is constant. The experiment consisted of using a piston, or in this case a syringe. Weights were attached to the syringe so that it would pull the piston down. First we found the weight that it took to make the piston move at a constant rate which gives us the frictional force. Once this was done there were a series of constant volumes which were measured and weights were added at small increments and the area they displaced was measured. After measured the data was then put into and excel chart to find their slopes. These slopes and their y intercepts are then used to find the pressure of the system and compared it to the actual pressure measured by a barometer. With the pressures we prove that as the volume is decreased the pressure is increasing demonstrating Boyle's Law.
Calculations and Error Analysis:
The first calculations were in finding the frictional force of the syringe, this was easily done by measuring the weight at which it takes to move the plunger. Then we used the calculations from measuring the different pressures and volumes in the syringe as weight was added. These measurements gave a ratio of through which we then use to find the atmospheric pressure. b[(p/k)-(f/ka)]. We compare our findings to a barometer in the class to see how close they are to one another. We had an average of 6% difference in our readings. This difference is easily accounted for as the plunger was of low caliber and didn't move exactly straight line or smoothly down the syringe.