Physics M.C.Q (1 Marks)

The atoms of gas have the most interatomic space and can therefore travel freely. This is why they travel longer distances without colliding and are therefore said to have the maximum mean free path.

Interatomic forces are attractive in long range and repulsive in short range and negligible in gases.

Latent heat of ice is more than external latent heat of fusion.

At low pressure, the concentration of gas molecules is very low. Hence, the kinetic assumption that the size of the molecules can be neglected compared to the volume of the container applies. At high temperature, molecules move very fast. So, they tend to collide elastically and forces of interaction between the molecules minimise. This is the required idea condition.

As we know kinetic energy of molecules of a gas is a function of Temperature
So, As we decrease its temperature or say cool it, its kinetic energy gradually decrease.
At a certain point which decreasing kinetic energy it starts bonding up whit molecules and thus condensation starts.

The molecules move in all possible directions in an ideal gas at equilibrium.
Since momentum is a vector quantity for every direction of motion of the molecules, there exists an opposite direction of motion of the other.
Hence, the average momentum is zero for an ideal gas at equilibrium.

If heat is coming into a substance during a phase change, then this energy is used to break the bonds between the molecules of the substance.
An example we will use here is ice melting into water.

When two bodies at different temperatures are mixed in the calorimeter, heat flows from one body to the other due to the temperature difference. This results in change in the internal energy of the individual bodies. There is no exchange of heat with the surrounding in the calorimeter. Thus, the total internal energy of the bodies remain conserved as no external work is done on them.

Internal energy is dependent on the freedom of movement of particles.
Since in gaseous state, particles are most free to move, this state has maximum internal energy.

Real gases approach ideal gas behaviour at high temperature and low pressure because at high pressures and low temperature, molecules of gases are very close to each other.

The heat energy supplied per unit mass of a substance at its melting point to convert the state of the substance from solid to liquid is known as Latent heat of Fusion.