Chemical Engineering Thermodynamics MCQ Questions & Answers | Chemical Engineering

Since here the solid or semi solid state is converting to liquid state the freedom of molecules is increasing hence randomness increases thereby, entropy which is an measure of randomness also increases.

For a perfect gas since, the enthalpy depends only on temperature and the joule Thomson coefficient which is ratio of temperature change to pressure change at constant enthalpy. Since for an perfect gas the enthalpy remaining constant leads to temperature constancy the joule Thomson coefficient becomes zero.

Activity coefficient \[{{\gamma }_{i}}=\frac{{{\overset\frown{{{f}_{l}}}}^{real}}}{\overset\frown{{{f}_{l}}^{ld}}}\]
For an ideal solution activity coefficient $$= 1$$
And for real solution it tells about the departure from ideal solution by real solution like compressibility factor in case of gases.

The Carnot refrigeration cycle is just reverse of heat engine cycle where it takes heat from low temperature reservoir and by the help of external work it give the heat to high temperature reservoir.

A refrigerator can also be termed as heat pump as both functions on a same way that is taking heat from low temperature reservoir and by the help of external work giving heat to high temperature reservoir.

Since the moles of reactants is less than the products by Le Chatelier's principle we can say decreasing the pressure will increases the dissociation of $$PC{l_5}.$$

The relation between the state properties is given by Maxwell’s equation which relates the state properties the relation between the given $$P,V,T,S$$   is $${\left( {\frac{{\partial T}}{{\partial V}}} \right)_S} = {\left( {\frac{{\partial P}}{{\partial S}}} \right)_V}.$$

Since to melt the ice we provide heat (energy) the reaction is endothermic we can say enthalpy change is positive.

For an isolated system the entropy change is always goes on increasing (second law of thermodynamics). Given, the system and surroundings are taken together that means the resulting system will be an isolated system and in that isolated system if the interactions between the system and surroundings are irreversible we the entropy change will be greater than zero and if the interactions are reversible the entropy change will be equal to zero.
$$\Delta {S_{isolated\,\,system}} \geqslant 0$$