Question

In this simulation, you will be exploring the relationship between temperature and pressure while keeping volume constant. Click here to begin. Select the Explore box. Answer the questions as you perform the steps.

1. Raise and push down the pressure pump handle to add gas molecules to the container. The initial temperature is 300 K (27°) and the pressure has a range of 5.4–6.2 atm. Notice the pressure values change as the particles collide with the wall.

2. Click on the bucket to raise the temperature of the container to approximately 400 K (127°C). What happened to the pressure?
Approximately what pressure range did you observe?

3. Click on the bucket to reduce the temperature to approximately 200 K (−73°C). What happened to the pressure?
Approximately what pressure did you observe?

4. What gas law mathematically shows the relationships between temperature and pressure?

Answer 1

2. When you raised the temperature to ~400 K the pressure increased.
Approximate pressure range observed: about 7.2–8.3 atm (P ≈ initial P × 400/300).

3. When you reduced the temperature to ~200 K the pressure decreased.
Approximate pressure observed: about 3.6–4.1 atm (P ≈ initial P × 200/300).

4. The relationship is given by Gay‑Lussac’s law (the pressure law): at constant volume and amount of gas, P ∝ T, or P1/T1 = P2/T2 (use T in kelvin).