Question

: Van Der Waals real gas, acts as an ideal gas at which condition?
A.High temperature, low pressure
B.Low temperature, high pressure
C.High temperature, high pressure
D.Low temperature, low pressure

Answer 1

To answer this question, you should recall the concept of ideal gas equation Ideal gases are the gases which have elastic collisions between their molecules and there are no intermolecular attractive forces. In reality, there is no such thing as ideal gases. The gases just show ideal behaviour under certain conditions of temperature and pressure.
Formula used:
$PV = nRT$
where $P$ is pressure, $V$ is volume, $R$ is the universal gas constant, $n$ is no. of moles and $T$ is temperature

Complete answer:
At higher temperature and low-pressure real gas acts as an ideal gas and obey $PV = nRT$ where $P$ is pressure, $V$ is volume, $R$ is the universal gas constant, $n$ is no. of moles and $T$ is temperature
Here, it is assumed that:
-The ideal gases are made up of molecules which are in constant motion in random directions.
-The molecules of an ideal gas behave as rigid spheres.
-All the collisions are elastic.
-The temperature of the gas is directly proportional to the average kinetic energy of the molecules.
-Pressure occurs due to the collision between the molecules with the walls of the container.

Hence, the correct option is option A.

Note:
Make sure you remember that at conditions of high temperature and lower pressure, a real gas behaves like an ideal gas, because the potential energy due to intermolecular attractive forces becomes less significant compared with the particles’ kinetic energy, and the size of the molecules becomes less significant compared to the space between them. Along with different speeds, you should know the concept of the Maxwell-Boltzmann equation. The five gas laws are:
-Boyle’s Law establishes a relationship between the pressure and the volume of a gas.
-Charles’s Law establishes a relationship between the volume occupied by a gas and the absolute temperature.
-Gay-Lussac’s Law establishes a relationship between the pressure exerted by a gas on the walls of its container and the absolute temperature associated with the gas.
-Avogadro’s Law establishes a relationship between the volume occupied by a gas and the amount of gaseous substance.
-After combining these four aforementioned laws we arrive at the Combined Gas Law.