Notes:

From class on Wednesday, September 8:

Let's look at STEP #1 ONLY to find a critical point for the van der Waals equation:

van der Waals:

And, to determine a critical point,  we need to solve:

We can solve for:

Now, let's just focus on the first derivative (you should work through the second derivative and bring your results to class on Friday - Simply take the second derivative for now - you do NOT need to solve for zero yet.)

We can pull out the constants:

And, if we prefer,  we can express:

and

and rewrite the above dp/dV_m equation as:

Now, taking the derivative, let's review some of our calculus:

Let's take our dp/dV_m derivative:

which we set =0.     Now, for class on Friday, take the second derivative.