Real Gas PV Curve: Volume Explained

In summary, a real gas PV curve is a graph that shows the relationship between pressure and volume of a gas at a constant temperature. The volume of a gas is inversely related to its pressure, following Boyle's Law. Deviations from the ideal gas law on a real gas PV curve are caused by intermolecular forces between gas particles. Temperature affects the shape of the curve by shifting it left or right. Practical applications of the curve include studying gas behavior in industrial processes and designing gas storage containers.
  • #1
abcd8989
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http://faculty.wwu.edu/vawter/PhysicsNet/Topics/Thermal/gifs/vdWaalEOS02.gif
After the gas has been liquified, the gas volume should have disappeared. Why the liquid part of the curve still possesses volume?
 
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  • #2
Think about it for a few minutes, please.
 
  • #3
Isn't the volume under consideration the gas volume? When the gas is liquified, there should be no volume...
 
  • #4
No, the volume under consideration is the complete volume. Liquid still possesses volume, though it is much smaller than the gas volume.
 
  • #5


The reason for the liquid portion of the curve still possessing volume is due to intermolecular forces. In a real gas, the molecules are not ideal and therefore, they interact with each other through attractive and repulsive forces. In the liquid state, the molecules are close enough to each other for these forces to become significant, causing the molecules to be held together in a specific volume. This is why even when a gas is condensed into a liquid, it still maintains a certain volume. The behavior of real gases is more accurately described by the van der Waals equation of state, which takes into account these intermolecular forces.
 

1. What is a real gas PV curve?

A real gas PV curve is a graph that represents the relationship between the pressure (P) and volume (V) of a gas at a constant temperature. It is used to study the behavior of real gases, which do not always follow the ideal gas law.

2. How is the volume of a gas related to its pressure?

The volume of a gas is inversely related to its pressure, meaning that as the pressure increases, the volume decreases and vice versa. This relationship is known as Boyle's Law and is represented by a curved line on a real gas PV curve.

3. What causes deviations from the ideal gas law on a real gas PV curve?

Real gases deviate from the ideal gas law due to intermolecular forces between gas particles, which are not accounted for in the ideal gas law. These forces become more significant at high pressures and low temperatures, causing the gas to occupy a smaller volume than predicted by the ideal gas law.

4. How does temperature affect the shape of a real gas PV curve?

Temperature affects the shape of a real gas PV curve by shifting the curve to the left or right. As temperature increases, the curve shifts to the right, indicating an increase in volume at a given pressure. On the other hand, as temperature decreases, the curve shifts to the left, indicating a decrease in volume at a given pressure.

5. What practical applications does the real gas PV curve have?

The real gas PV curve has several practical applications in fields such as chemistry and engineering. It is used to study the behavior of real gases in industrial processes, determine the compressibility of gases, and design gas storage containers that can withstand high pressures. It is also used to calculate the work done by a gas during a chemical reaction.

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