Chemical Engineering Thermodynamics MCQ Questions & Answers | Chemical Engineering

According to Henrys law the solubility increases with increase in pressure at a particular temperature and the relation is
$$S = H * P$$
Where :
$$S$$ = solubility
$$H$$ = henrys constant
$$P$$ = pressure.

Chemical engineering thermodynamics is more concerned with the equilibrium states behavior. How much energy or mass is present at equilibrium like what is the equilibrium concentration, temperature etc. or we can say by basic thermodynamics the amount of energy transferred from one form to another by the use of first law of thermodynamics.
But, basically the chemical engineering thermodynamics deals with equilibrium states.

Only below and at the critical point there is strong demarcation in properties of liquids and gases above the critical point we can’t recognize the difference. Hence for a gas which is under or at the critical point can be liquefied. For a gas above critical point can also undergo a pressure change but we can’t notice the difference in properties.

Closed system is also called as control mass system where there is no exchange of mass between system and surroundings but energy transfer can takes place. In closed system there shouldn`t be change in identity of mass (molecules) of system even.

clausis-claperyon equation can be applied for any equilibrium system consisting of two phases the two phases can be solid and liquid during melting or solid and vapor during sublimation and the relation is given as.
$$lnP = \frac{{ - \Delta {H_{phase\,\,change}}}}{{RT}} + C$$

For any spontaneous process $$dG \leqslant 0,\,\,dA \leqslant 0$$
And usually spontaneous process takes place when there are finite differences so, the process will be usually irreversible.
Hence $$dG < 0\,\,\& \,\,dH < 0$$
So, free energy goes on decreasing and when the finite difference becomes infinitesimal difference it becomes constant.

Above the inversion temperature joule-thomson coefficient $${\left( {\frac{{\partial T}}{{\partial P}}} \right)_H} = - ve$$
So, by throttling (decreasing the pressure) the temperature increases and hence heating.
Below the inversion temperature houle-thomson coefficient $${\left( {\frac{{\partial T}}{{\partial P}}} \right)_H} = + ve$$
So,by throttling the temperature decreases hence cooling.

Refrigeration works on one of the corollary of second law of thermodynamics namely clausius statement. Which states that heat can’t be continuously transferred from low temperature reserviour to high temperature reserviour without using some external work. Where the work is supplied in the form of electricity.

The property temperature emerged from zeroth law of thermodynamics which states that when two bodies are contacted by heat permeable wall we call that as diabetic wall than the system will reach thermal equilibrium only when thermal energy in both the systems are equal and temperature is an measure of thermal energy. So, by this law temperature can be said as thermodynamic property. And its value gives how far is the system from reaching thermodynamic equilibrium.

Refrigeration works on one of the corollary of second law of thermodynamics namely clausius statement. Which states that heat can’t be continuously transferred from low temperature reserviour to high temperature reserviour without using some external work. Where the work is supplied in the form of electricity.