Solution:

For cooling to take place by throttling the Joule-Thomson coefficient must be negative. $${\left( {\frac{{\partial T}}{{\partial P}}} \right)_H} = - VE.$$

Solution:

Fugacity is nothing but the effective pressure or escaping tendency of a particular component in a particular phase higher its value higher is the tendency to escape to other phase hence the name.

Solution:

Fugacity for ideal gas is equal to its pressure but for a real gas it is not equal to pressure higher the difference higher is the non-ideality actually the fugacity coefficient acts as an measure of non-ideality.

Solution:

Here if we consider the universe is consisting of heat engine and corresponding high and low temperature reservoirs and to take the heat from the heat engine an surrounding as the components in the universe, than as the process goes on the temperature of the hot reservoir decreases and at some point the temperature of the universe becomes uniform and no more conversion of heat to work takes place. So, we can say as the spontaneous process is taking place in the universe the entropy is increasing of the universe and the heat engine efficiency is decreasing as the temperature is gradually becoming uniform throughout the universe.

Solution:

An equation of state must connect the basic properties of a substance like temperature, pressure and volume of the substance (system).

Solution:

Since, during phase change we provide latent heat (enthalpy) for breaking the intermolecular forces obviously the enthalpy changes and also since there will be the difference in potential energy between two different phases the internal energy also changes.

Solution:

The given are Van der waals equation of state and ideal equation of state and virial equation of state.