Chemical Engineering Thermodynamics MCQs

Near their critical temperatures, all gases occupy volumes __________ that of the ideal gas.

An isolated system can exchange __________ with its surroundings.

The co-efficient of performance (COP) of a refrigerating system, which is its index of performance, is defined as the ratio of useful refrigeration to the net work. The units of __________ and COP are the same.

Domestic refrigerator usually works on the __________ refrigeration cycle.

At absolute zero temperature, the __________ of the gas is zero.

The melting point of paraffin wax (which contracts on solidification) __________ with pressure rise.

The expression for entropy change given by, $$\Delta {\text{S}} = {\text{nR}}l{\text{n}}\left( {\frac{{{{\text{V}}_2}}}{{{{\text{V}}_1}}}} \right) + {\text{n}}{{\text{C}}_{\text{v}}}l{\text{n}}\left( {\frac{{{{\text{T}}_2}}}{{{{\text{T}}_1}}}} \right)$$ is valid for

On a P-V diagram of an ideal gas, suppose a reversible adiabatic line intersects a reversible isothermal line at point A. Then at a point A, the slope of the reversible adiabatic line $${\left( {\frac{{\partial {\text{P}}}}{{\partial {\text{V}}}}} \right)_{\text{S}}}$$ and the slope of the reversible isothermal line $${\left( {\frac{{\partial {\text{P}}}}{{\partial {\text{V}}}}} \right)_{\text{T}}}$$ are related as (where, $${\text{y}} = \frac{{{{\text{C}}_{\text{p}}}}}{{{{\text{C}}_{\text{v}}}}}$$ )

Trouton's ratio is given by (where $${\lambda _{\text{b}}}$$ = molal heat of vaporisation of a substance at its normal boiling point, kcal/kmol Tb = normal boiling point, °K )