Driving question: How are pressure, temperature, and volume related in a gas?
Introduction & Background:
The purpose of this experiment is to better understand how pressure, temperature and volume are related in a gas. Two experiments are performed to study the properties of gases. In the first experiment, the pressure is related to the volume of gases at room temperature using a syringe that is connected to a pressure sensor. The pressure changes will be monitored as the volume of the captured gases changes (The plunger is pushed in, decreasing the volume). In the second experiment, the volume of the gas remains constant, and the change in pressure of the gas is monitored as the temperature is increased. A hot plate is used to heat an Erlenmeyer flask, that is submerged in a water bath. A temperature sensor and pressure sensor is placed inside the Erlenmeyer flask to monitor the changes of pressure as the temperature increases.
The atoms or molecules of solids and liquids are very close to each other, which cannot be measurably compressed. The atoms or molecules in gases, on the other hand, have relatively large distances between them, which allows gases to be compressed.
Gas pressure is related to the frequency of gas molecules bouncing into surfaces. Therefore, as the volume of the container is changed, the time it takes for the molecules to get from one wall to another changes. As the volume decreases, the pressure increases, and vice versa.
The temperature is a measure of the average kinetic energy of gas molecules. As the temperature changes, the time it takes for molecules to move from wall to wall in a container changes. The colder a gas becomes, the slower molecules move, therefore the pressure at which all motion stops between the molecules is zero pressure. The temperature at which the pressure is at zero is called "absolute zero".