1. Consider the intermolecular interaction potential shown below
Consider the intermolecular interaction potential shown below. Which part of the potential dominates at which temperature regime?
Low T: repulsion; high T: attraction.
Low T: attraction; high T: repulsion.
The dominant contribution is independent of T, it is always the repulsive part.
The dominant contribution is independent of T, it is always the attractive part.

2. Consider the intermolecular interaction potential shown below
Consider the intermolecular interaction potential shown below. Which part of the potential dominates at which temperature regime?
Low T: repulsion; high T: attraction.
Low T: attraction; high T: repulsion.
The dominant contribution is independent of T, it is always the repulsive part.
The dominant contribution is independent of T, it is always the attractive part.

3. What describes the critical point mathematically?
The first derivative of the critical isotherm is zero.
The first and the second derivative of the critical isotherm are both zero.
The second and the third derivative of the critical isotherm are both zero.

4. What describes the critical point mathematically?
The first derivative of the critical isotherm is zero.
The first and the second derivative of the critical isotherm are both zero. p(V) is flat (dp/dV = 0) and has an inflection point (d2p/dV2=0)
The second and the third derivative of the critical isotherm are both zero.