Explore topic-wise MCQs in Chemical Engineering.

This section includes 838 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.

351.

The accentric factor of a materical, 'ω', is defined as ω = -log10(Prsat)Tr⁻¹ = 0.7, where, Prsat = reduced vapor pressure, Tr = reduced temperature. The value of accentric factor is always

A. > 2
B. < 1
C. > 1
D. < 3
Answer» C. > 1
352.

The ammonia synthesis reaction represented by N₂ + 3H₂ ⇋ 2NH₃ ; ΔH = - 22.4 kcal, is

A. Endothermic
B. Exothermic
C. Isothermal
D. Adiabatic
Answer» C. Isothermal
353.

The equation relating E, P, V and T which is true for all substanes under all conditions is given by (∂E/∂V)T = T.(∂P/∂T)H - P . This equation is called the

A. Maxwell
B. Thermodynamic equation of state
C. Equation of state
D. Redlich-Kwong equation of state
Answer» C. Equation of state
354.

Sublimation temperature of dry ice (solid CO₂) is __________ °C.

A. -273
B. 0
C. -78
D. 5
Answer» D. 5
355.

Melting of ice is an example of an __________ process.

A. adiabatic
B. isothermal
C. isometric
D. none of these
Answer» C. isometric
356.

Which law of the thermodynamics provids basis for measuring the thermodynamic property ?

A. First law
B. Zeroth law
C. Third law
D. Second law
Answer» C. Third law
357.

A solute distributes itself between two non-miscible solvents in contact with each other in such a way that, at a constant temperature, the ratio of its concentrations in two layers is constant, irrespective of its total amount". This is

A. the distribution law.
B. followed from Margule's equation.
C. a corollary of Henry's law.
D. none of these.
Answer» B. followed from Margule's equation.
358.

If the heat of solution of an ideal gas in a liquid is negative, then its solubility at a given partial pressure varies with the temperature as

A. solubility increases as temperature increases.
B. solubility increases as temperature decreases.
C. solubility is independent of temperature.
D. solubility increases or decreases with temperature depending on the Gibbs free energy change of solution.
Answer» C. solubility is independent of temperature.
359.

Molar heat capacity of water in equilibrium with ice at constant pressure is __________ Kcal/kg mole . °K$

A. 0
B. ‚àû
C. 50
D. 100
Answer» C. 50
360.

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

A. work required to refrigeration obtained.
B. refrigeration obtained to the work required.
C. lower to higher temperature.
D. higher to lower temperature.
Answer» C. lower to higher temperature.
361.

The partial pressure of each constituent present in an alloy is __________ the total vapor pressure exerted by the alloy.

A. less than
B. equal to
C. more than
D. either (b) or (c); depends on the type of alloy
Answer» B. equal to
362.

Third law of thermodynamics is concerned with the

A. value of absolute entropy.
B. energy transfer.
C. direction of energy transfer.
D. none of these.
Answer» B. energy transfer.
363.

In any spontaneous process, the __________ free energy decreases.

A. Helmholtz
B. Gibbs
C. both a & b
D. neither 'a' nor 'b'
Answer» D. neither 'a' nor 'b'
364.

Which of the following is an undesirable characteristics of a refrigerant ?

A. It should be non-explosive.
B. It should have a sub-atmospheric vapor pressure at the temperature in refrigerator coils.
C. Its vapor pressure at the condenser temperature should be very high.
D. None of these.
Answer» C. Its vapor pressure at the condenser temperature should be very high.
365.

With increase in temperature, the atomic heat capacities of all solid elements

A. increases
B. decreases
C. remains unchanged
D. decreases linearly
Answer» B. decreases
366.

The first law of thermodynamics is a restatement of the law of conservation of

A. mass
B. energy
C. momentum
D. none of these
Answer» C. momentum
367.

The unity of Planck's constant 'h' in the equation, E = hv is

A. J/s
B. J.S
C. J/kmol
D. kmol/J
Answer» C. J/kmol
368.

A gas has a volume of 27.3 c.c. at 0°C. Its volume at 10°C (if pressure remains unchanged) will be __________ c.c.$

A. 2.73
B. 28.3
C. 273
D. 283
Answer» C. 273
369.

Change of state namely evaportation condensation, freezing and melting is an __________ process.

A. isothermal
B. adiabatic
C. isobaric
D. isochoric
Answer» B. adiabatic
370.

Gibbs free energy per mole for a pure substance is equal to the

A. latent heat of vaporisation
B. chemical potential
C. molal boiling point
D. heat capacity
Answer» C. molal boiling point
371.

Free energy changes for two reaction mechanism 'X' and 'Y are respectively - 15 and - 5 units. It implies that X is

A. slower than Y
B. faster than Y
C. three times slower than Y
D. three times faster than Y
Answer» C. three times slower than Y
372.

A nozzle is a device, which

A. increases kinetic energy and decreases pressure.
B. reduces kinetic energy and increases pressure.
C. reduces both kinetic energy and pressure.
D. increases both kinetic energy and pressure.
Answer» B. reduces kinetic energy and increases pressure.
373.

The total change in the enthalpy of a system is independent of the

A. number of intermediate chemical reactions involved.
B. pressure and temperature.
C. state of combination and aggregation in the beginning and at the end of the reaction.
D. none of these.
Answer» B. pressure and temperature.
374.

The effect of changing the evaporator temperature on COP as compared to that of changing the condenser temperature (in vapour compression refrigeration system) is

A. less pronounced
B. more pronounced
C. equal
D. data insufficient, can't be predicted.
Answer» C. equal
375.

Which of the following processes can not be made reversible even under ideal condition of operation?

A. Free expansion of a gas.
B. Compression of air in a compressor.
C. Expansion of steam in a turbine.
D. all (a), (b) & (c).
Answer» B. Compression of air in a compressor.
376.

Which is not a refrigerant ?

A. SO2
B. NH3
C. CCl2F2
D. C2H4Cl2
Answer» E.
377.

In case of the decomposition of hydroiodic acid (2HI H2 + I2), addition of H2 (at equilibrium condition) will

A. increase the partial pressure of I2.
B. decrease the partial pressure of HI.
C. diminish the degree of dissociation of HI.
D. none of these.
Answer» D. none of these.
378.

Minimum number of phases that exists in a system is 1. Number of chemical species in a colloidal system is

A. 1
B. 4
C. 2
D. 3
Answer» D. 3
379.

Adiabatic compression of a saturated water vapour makes it

A. supersaturated
B. superheated
C. both (a) and (b)
D. neither (a) nor (b)
Answer» C. both (a) and (b)
380.

The point at which all the three (solid, liquid and gas) phases co-exist, is known as the __________ point.

A. freezing
B. triple
C. boiling
D. Boyle
Answer» C. boiling
381.

In which of the following reaction equilibria, the value of equilibrium constant Kp will be more than is Kc ?

A. 2HI H2 + I2
B. N2O4 2NO2
C. 2SO2 + O2 2SO3
D. none of these
Answer» C. 2SO2 + O2 2SO3
382.

The first law of thermodynamics is a statement of conservation of

A. heat
B. momentum
C. energy
D. work
Answer» D. work
383.

An ideal liquid refrigerant should

A. not have a subatmospheric vapour pressure at the temperature in the refrigerator coils.
B. not have unduly high vapour pressure at the condenser temperature.
C. both (a) and (b).
D. have low specific heat.
Answer» D. have low specific heat.
384.

"If different processes are used to bring about the same chemical reaction, the enthalpy change is same for all of them". This is __________ law.

A. Hess's
B. Kirchoff's
C. Lavoisier and Laplace
D. none of these
Answer» B. Kirchoff's
385.

Internal energy is equal to the heat absorbed in case of a/an __________ process.

A. constant volume
B. polytropic
C. adiabatic
D. constant pressure
Answer» B. polytropic
386.

For spontaneous changes in an isolated system (S = entropy)

A. ds = 0
B. ds <0
C. ds > 0
D. ds = Constant
Answer» D. ds = Constant
387.

The expression for entropy change given by, ΔS = nR ln (V2/V1) + nCv ln (T2/T1) is valid for$

A. reversible isothermal volume change.
B. heating of a substance.
C. cooling of a substance.
D. simultaneous heating and expansion of an ideal gas.
Answer» E.
388.

Partial molal quantities are important in the study of

A. ideal gases
B. ideal solutions
C. non-ideal mixtures
D. a pure component
Answer» D. a pure component
389.

Which of the following non-flow reversible compression processes require maximum work ?

A. Adiabatic process
B. Isothermal process
C. Isobaric process
D. All require same work
Answer» B. Isothermal process
390.

In the reaction, represented by, 2SO2 + O2 2SO3; ΔH = - 42 kcal; the forward reaction will be favoured by$

A. low temperature
B. high pressure
C. both (a) and (b)
D. neither (a) nor (b)
Answer» D. neither (a) nor (b)
391.

Consider the reaction, C + O2 CO2 ;ΔH = - 94 kcal. What will be the value of ΔH for the reaction CO2 C + O2 ?$

A. -94 kcal
B. + 94 kcal
C. > 94 kcal
D. < -94 kcal
Answer» C. > 94 kcal
392.

The entropy change in a reversible isothermal process, when an ideal gas expands to four times its initial volume is

A. R loge 4
B. R log10 4
C. Cv log10 4
D. Cv loge 4
Answer» B. R log10 4
393.

One mole of nitrogen at 8 bar and 600 K is contained in a piston-cylinder arrangement. It is brought to 1 bar isothermally against a resisting pressure of 1 bar. The work done (in Joules) by the gas is

A. 30554
B. 10373
C. 4988.4
D. 4364.9
Answer» C. 4988.4
394.

The number of degrees of freedom for a mixture of ice and water (liquid) are

A. 2
B. 3
C. 1
D. 0
Answer» D. 0
395.

The chemical potential of any constituent of an ideal solution depends on the __________ of the solution.

A. temperature
B. pressure
C. composition
D. all (a), (b) and (c)
Answer» E.
396.

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 (∂P/∂V)s and the slope of the reversible isothermal line (∂P/∂V)T are related as (where, y = Cp/Cv)$

A. (∂P/∂V)S = (∂P/∂V)T
B. (∂P/∂V)S = [(∂P/∂V)T]Y
C. (∂P/∂V)S = y(∂P/∂V)T
D. (∂P/∂V)S = 1/y(∂P/∂V)T
Answer» D. (‚àÇP/‚àÇV)S = 1/y(‚àÇP/‚àÇV)T
397.

Pressure-enthalpy chart is useful in refrigeration. The change in internal energy of an ideal fluid used in ideal refrigeration cycle is

A. positive
B. negative
C. zero
D. infinity
Answer» D. infinity
398.

Kopp's rule is used to calculate the heat capacity of

A. solids
B. liquids
C. gases
D. all (a), (b) & (c)
Answer» B. liquids
399.

Refrigeration cycle

A. violates second law of thermodynamics.
B. involves transfer of heat from low temperature to high temperature.
C. both (a) and (b).
D. neither (a) nor (b).
Answer» C. both (a) and (b).
400.

A closed system is cooled reversibly from 100°C to 50°C. If no work is done on the system$

A. its internal energy (U) decreases and its entropy (S) increases.
B. U and S both decreases
C. U decreases but S is constant.
D. U is constant but S decreases.
Answer» C. U decreases but S is constant.