Chemical Engineering Thermodynamics MCQ Questions & Answers | Chemical Engineering

According to Le Chatelier's principle increase in temperature for an exothermic reaction will favor backward reaction and hence the product concentrations decreases and an new equilibrium is reached for an particular decrease in temperature and therefore the equilibrium constant decreases not increases.
$${K_c} = \frac{{C * D}}{{A * B}}.$$

By first law of thermodynamics for a system undergoing only expansion work we can write $$\delta Q = dU + PdV$$
For an isochoric process since $$dV=0$$   we can write $$\delta Q = dU.$$

With an increase in pressure the melting and boiling points for most of the substances increases except for some of the liquids like water etc. Where with increase in pressure the melting point decreases. Refer phase diagrams (P-T) plots of pure substances.

A Carnot cycle is a reversible cycle consists of four processes.
I. Reversible isothermal expansion.
II. Reversible adiabatic expansion (isentropic).
III. Reversible isothermal compression.
IV. Reversible adiabatic compression (isentropic).

Always during throttling there is viscous dissipation which tries to increase the intermolecular energy and there by the temperature of the fluid which is non-conservative in nature so, the throttling is considered as irreversible process and we usually conduct this in an adiabatic container and if we see only the intermolecular energy and the pressure energy inter conversion takes place maintaining the enthalpy constant the pressure energy only converts to the intermolecular energy.

Gibbs free energy:
$$\eqalign{ & G = H - TS \cr & \Rightarrow - dG = {W_R} - PdV \cr} $$
So, the decrease in Gibbs energy represents maximum useful work (excluding the expansion work) in a reversible process under isothermal and isobaric conditions.

According to second law of thermodynamics, the entropy $${\left( {ds} \right)_{universe}} > 0,$$   for an irreversible or spontaneous process and $$d{s_{universe}} > 0$$   for an reversible process or almost equilibrium reached process. So for a natural process since there will be irreversibility always the system entropy goes on increasing until equilibrium is reached and once the system reaches the equilibrium the system entropy becomes equal to zero. Hence a maximum exists for a system.

The evaporator plays a major role during the vapour compression refrigeration system.

The given is the statement of the Lewis-Randall rule
$${f_i} = {f_i}^0{X_i}$$