Chemical Engineering Thermodynamics MCQs

Question 1

Which of the following equations is obtained on combining 1st and 2nd law of thermodynamics, for a system of constant mass?

Accepted Answer

dE = Tds - PdV

Answer

dQ = CvdT + PdV

Answer

dQ = CpdT + Vdp

Answer

Tds = dE - PdV

Question 2

For an exothremic reaction

Accepted Answer

Both ΔH and ΔE are negative

Answer

Only enthalpy change (ΔH) is negative

Answer

Only internal energy change (ΔE) is negative

Answer

Enthalpy change is zero

Question 3

For an ideal gas, the enthalpy

Accepted Answer

Is independent of pressure

Answer

Increases with rise in pressure

Answer

Decreases with rise in pressure

Answer

Is a path function

Question 4

Refrigerants commonly used for domestic refrigerators are

Accepted Answer

Ethyl chloride or methyle chloride

Answer

Freon-12

Answer

Propane

Answer

NH3 or CO2

Question 5

Which of the following is true for Virial equation of state?

Accepted Answer

Virial co-efficients are function of temperature only

Answer

Virial co-efficients are universal constants

Answer

Virial co-efficients

Answer

For some gases, Virial equations and ideal gas equations are the same

Question 6

A reasonably general expression for vapour-liquid phase equilibrium at low to moderate pressure is Φi yi P = Yi xi fi° where, Φ is a vapor fugacity component, Yi is the liquid activity co-efficient and fi° is the fugacity of the pure component i. the Ki value (Yi = Ki xi) is therefore, in general a function of

Accepted Answer

Temperature, pressure and liquid composition xi only

Answer

Temperature only

Answer

Temperature and pressure only

Answer

Temperature, pressure, liquid composition xi and vapour composition yi

Question 7

Pick out the wrong statement.

Accepted Answer

The entropy of a substance does not remain constant during a reversible adiabatie change

Answer

The net change in entropy in any reversible cycle is always zero

Answer

The entropy of the system as a whole in an irreversible process increases

Answer

The entropy of the universe tends to a maximum

Question 8

Free energy

Accepted Answer

All of the above

Answer

Decreases in all spontaneous (or irreversible) processes

Answer

Change during a spontaneous process has a negative value

Answer

Remains unchanged in reversible processes carried at constant temperature and pressure

Question 9

Co-efficient of Performance (COP) of a refrigerator is the ratio of the

Accepted Answer

Refrigeration obtained to the work required

Answer

Work required to refrigeration obtained

Answer

Lower to higher temperature

Answer

Higher to lower temperature