Boyle's law states that volume and pressure are inversely proportional at constant moles and temperature. It's named after Robert Boyle and it illustrates how the volume of a container is greatly affected by pressure changes. Now, how do we depict this relationship? When we say they're inversely proportional, we can say that they're on different levels. So we're going to say volume is inversely proportional to pressure, which means that V ∝ 1P. This shows our inverse relationship between volume and pressure. Think of it as volume being a numerator, and pressure being a denominator. They're on different levels, so they are different from one another. If one goes up, the other one has to go down.
Now, this is illustrated if we take a look at variables. Here we have two containers with movable pistons. Volume is just the space within my container. So, if we look at this image we can say that the volume is pretty high. Pressure represents the downward force that we have on the piston. Now, the downward force on the piston must be pretty low, which is why the piston hasn't slid down lower. Here we can see volume is high, pressure is low. Now, let's say that we garnered enough force from the pressure we're able to push down on this piston. We can see that the volume now is smaller, so the volume now is low and that's a direct result of the pressure being higher.
Now, how do we depict this inverse relationship graphically? Well, to show an inverse relationship between two variables, you would show it like this. This graph is showing me that my volume is decreasing over time and as a result, the pressure is increasing over time. This is how we depict an inverse relationship between two variables.
Now, how do we show Boyle's law formula in the form of a digested formula? Here we'd say that it becomes P1V1 = P2V2. This represents our adjusted formula, also our Boyle's law formula where P1 is our initial pressure, V1 is our initial volume, P2 is our final pressure, and V2 is our final volume. Now remember, we went over how we derived these different types of formulas under the ideal gas laws application section. If you don't know what that is or if you haven't seen those videos yet, I suggest you go back and take a look at how we can derive this formula. Now we just know that it's connected to Boyle's law and therefore called the Boyle's law formula. So keep this in mind. Boyle's law says that pressure and volume are inversely proportional, meaning if one is high the other one would be low.