Question

At Boyle temperature:
A.The effects of the repulsive and attractive intermolecular forces just offset each other
B.The repulsive intermolecular forces are greater than the attractive intermolecular forces
C.The repulsive intermolecular forces are less than the attractive intermolecular forces
D.$b-\dfrac{a}{RT}>0$

Answer 1

Hint: The temperature at which the real or non-ideal gas behaves like an ideal gas over a wide range of pressure is known as Boyle temperature. Using this information, we can now solve the given question.

Complete answer:
- Boyle temperature (TB) is related to the Vander Waals constant a, b as show below
Boyle Temperature\[=\dfrac{a}{Rb}\]
- The Boyle temperature is the temperature at which a non-ideal/ real gas behaves approximately ideally for an appreciable range of pressure. In other words, a non-ideal gas behaves like an ideal gas.
- At this temperature the attractive forces and the repulsive forces acting on the gas particles arrive at a balance for a real gas.
- Therefore, vapor pressure of the system is equal to the atmospheric pressure.

Thus, the answer to the question is (A) The effects of the repulsive and attractive intermolecular forces just offset each other.

Additional information:
The ideal gas law assumes that gases are composed of point masses that interact via completely elastic collisions. Whereas, real gases are made up of particles that occupy a non-zero volume known as the excluded volume.

Note:
The van der Waals equation includes a volume-correction term that is specific to each gas. If a gas is behaving in an ideal manner, the correction term becomes negligible relative to the total volume.