Gas Experiments

The gas laws are a series of statements that describe the relationships between pressure P, volume V and temperature T of a fixed mass of gas. In this activity you will determine experimentally the relationship, for a fixed mass of gas, between

• pressure and volume

• pressure and temperature

You will also use a simulation to verify the relationship between pressure and volume and you will use a simulation to try to explain the gas laws in terms of the particle model of gases.

Relationship between pressure and volume of a fixed mass of gas at a fixed temperature

In this experiment it is assumed that the mass and temperature of air in the syringe are constant. This means that it is assumed that no air particles escape from the syringe and that the temperature of the air in the syringe is not changed when the air is compressed or depressed.

Apparatus

LabQuest2, gas pressure sensor with gas syringe

Instructions

Connect the Gas Pressure Sensor to a LabQuest2 and screw in the syringe when it has an initial volume of air of 10 cm³, as shown

Boyle's law simulation

The relation between pressure and volume was discovered independently by the Irishman Robert Boyle (1662) and the Frenchman Edme Mariotte (1676). In English speaking countries it is known as Boyle's law whilst in France and other European countries it is known as Mariottes Law. Read the instructions on the simulation below and use it to confirm the relationship you discovered experimentally.

Relationship between pressure and temperature of a fixed mass of gas at constant volume

In this experiment it is assumed that the mass and volume of air in the syringe are constant. This means that it is assumed that no air particles escape from the glass flask rubber tubing and that the volume of the flask and rubber tubing does not change.

Apparatus

LabQuest2, gas pressure sensor with rubber tubing and rubber stopper, temperature sensor, conical flask, beaker of water

Instructions

Set up the apparatus with the help of the diagram and picture below.

Gas laws simulation

Use the gas laws simulation below to explain the gas laws using the particle model. You can control the relative amounts of two gases, A and B with the pump handle. You can release gas with the release valve. The temperature can be raised and lowered, plus the volume can be locked or changed. Play around with it and record the relationships amongst p, V, n and T.