Preview - Ideal Gas Laws - Connected Chemistry 2019

What is pressure?

Pressure 🔗 is defined as force per unit area. It is represented by the ratio of force to area:

(P)ressure = (F)orce / Surface (A)rea

This means that the pressure on a surface depends both on the force that is applied to the surface and the size of the surface. A larger force on a surface leads to larger pressure. A larger surface with the same force against it leads to a smaller pressure.

What does this definition of pressure imply for our Bike Tire model? What constitutes the "surface area"? Where does the force come from? How do we calculate the pressure in a fixed volume gas container like the one in our model?

We will use our simple Bike Tire model to find answers to these questions. Run the model once or twice without changing any parameters. Just observe the "pressure over time" plot for a while (≈30 ticks). Then answer the questions below. 
Please do not spend more than 4 minutes with this task.

Questions

Please answer the questions below.

How does the "pressure over time" plot change when you run the model with 50 particles? Describe each distinct pattern you observe. (min 2 sentences)

If you did not change the parameters, you should have observed a plot similar to the one below. Find a word to describe the part that is marked with red? Also hypothesize: Why might we observe such a pattern? (min 3 sentences)

How do you think the value of "pressure" is calculated inside this bike tire? (min. 3 sentences)

Tip: Remember that pressure (P) is defined as F/A (force divided by the surface area). Try to think about these two questions: (1) "what is the surface area in this model?" and (2) "what applies force to the surface area in this model"?

Notes

These notes will appear on every page in this lesson so feel free to put anything here you'd like to keep track of.