A CAP question related to Van der Waals equation.

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Start date Mar 25, 2020
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Van der waals

In summary, the Van der Waals equation accounts for real gas behavior by considering the volume of gas molecules and the intermolecular forces between them. However, it has limitations as it does not account for the size and shape of molecules or interactions beyond nearest neighbors. It can only be used for real gases, not ideal gases, and is derived from a combination of the ideal gas law and two correction factors. The constants in the equation represent the strength of intermolecular forces and the volume of gas molecules for a specific gas.

Mar 25, 2020

aiyiaiyiai

Homework Statement: The equation of state for some gases can be approximately expressed in the following way:
(P + a*n^2/V^2 )V = nRT
where P is pressure, V is volume, n is the number of moles of a substance, V /n is molar volume, the volume of 1 mole of gas, T is temperature, R ≈ 8.3144621 J/mol·K is the gas constant, a is substance-specific van der Waals constant, in units of kPaL^2/mol^2 , where L means litres.
The following diagram shows the pressure of carbon disulphide gas in terms of volume per mole at temperature of 300 K. What is the van der Waals constant for this gas?

Relevant Equations: Maybe the typical form of van der waals equation?
And this is a MC question, answer is 1300.

Diagram is here.

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Mar 25, 2020

aiyiaiyiai

it's wired that it's a straight line...

FAQ: A CAP question related to Van der Waals equation.

1. What is the Van der Waals equation?

The Van der Waals equation is a mathematical expression that describes the behavior of real gases, taking into account intermolecular forces and the finite size of gas molecules. It is an improvement upon the ideal gas law, which assumes that gas molecules have no volume and do not interact with each other.

2. What are the variables in the Van der Waals equation?

The Van der Waals equation has three variables: pressure (P), volume (V), and temperature (T). These variables are used to calculate the behavior of a real gas under non-ideal conditions.

3. How is the Van der Waals equation derived?

The Van der Waals equation is derived from the ideal gas law by incorporating two correction factors: one for the attractive forces between gas molecules (a), and one for the volume occupied by the gas molecules (b). These correction factors account for the non-ideal behavior of real gases.

4. What is the significance of the Van der Waals equation?

The Van der Waals equation is important because it provides a more accurate description of the behavior of real gases compared to the ideal gas law. It is used in various fields of science and engineering, such as thermodynamics, chemistry, and chemical engineering, to predict the behavior of gases under non-ideal conditions.

5. Are there any limitations to the Van der Waals equation?

Yes, the Van der Waals equation has limitations. It is most accurate for gases at low pressures and high temperatures. It also does not account for other factors that can affect gas behavior, such as chemical reactions or phase changes. However, it is still a useful tool for understanding and predicting the behavior of real gases in many situations.