Chemical Engineering Thermodynamics MCQ Questions & Answers | Chemical Engineering

Since for an adiabatic process \[T{V^{\gamma - 1}} = {\rm{CONSTANT}}\]     and on integration of this equation we get \[ln\left( {\frac{{{T_2}}}{{{T_1}}}} \right) = - \left( {\left( {\gamma - 1} \right)ln\frac{{{V_2}}}{{{V_1}}}} \right)\]       since for expansion process \[{V_2} > {V_1}\]   Hence \[ \Rightarrow {T_2} < T_1\]
So, cooling takes place.

All the three will be effected by temperature and the relation between the temperature and fugacity is given by : \[{\left( {\frac{{\partial ln{f_i}}}{{\partial T}}} \right)_{P,n}} = \frac{{ - \overline {{H_l}} + {{\overline {{H_l}} }^{^ \circ }}}}{{R{T^2}}}\]
Activity co-efficient and temperature given by : \[\frac{{\partial lna}}{{\partial {T_P}}} = \frac{{{H^{^ \circ }} - H}}{{R{T^2}}}\]
Free energy and temperature is given by : \[{\left( {\frac{{\partial G}}{{\partial T}}} \right)_P} = S\]

A closed system is that in which there will be no mass transfer or material transfer but there will be energy transfer here the identity of system also remains same. Since in the given options these conditions are satisfied by liquid cooling system where our attention is on energy transfer rather than mass transfer.

Entropy of an ideal gas depends upon :
\[\Delta S = \int_{{T_i}}^{{T_f}} {\frac{{{C_P}dT}}{T} - nRln\left( {\frac{{{P_f}}}{{{P_i}}}} \right)} \]
\[ \Rightarrow \] it depends upon both temperature and pressure.

The chemical potential and fugacity of an real gas is related by :
\[\mu = {\mu ^ \circ } + RT\frac{{lnf}}{{{f^ \circ }}}\]
Where \[{f^ \circ } = \]   standard fugacity given $$=1$$

Partial molar properties are defined as in non ideal systems the molar properties of an component in an mixture is not equal to molar properties of the same component when present as pure component so as to designate the properties of individual components in the mixture we used partial molar properties.
These partial molar properties and the total mixture property is related as \[{M^t} = \sum {{x_i}\overline {{M_l}} } \]

Group contribution method is used to measure the critical properties.

The efficiency of an heat engine is given by \[\mathop \eta \limits^\iota = \frac{{{Q_1} - {Q_2}}}{{{Q_1}}}\]
For heat pump it is given by \[\mathop \eta \limits^\iota = \frac{{{Q_1}}}{{{Q_1} - {Q_2}}}\]
Where \[{{Q_1}}\] and \[{{Q_2}}\] are given by heat taken and heat given to the thermal reservoirs respectively.
\[ \Rightarrow {\left( {\mathop \eta \limits^\iota } \right)_{heat\,\,engine}} = \frac{1}{{{{\left( {\mathop \eta \limits^\iota } \right)}_{heat\,\,pump}}}}\]

The room temperature is considered as standard stat at which internal energy is considered or taken as zero basically it is considered as Datum for calculations of internal energy.

A critical point is a point where the physical distinction between the liquid and vapor vanishes since there will be no further difference in properties like surface tension, volume, density etc. Between the liquid and vapor. So we call the state of substance at and above the critical point as gas.