Principles and Practice of Chemical
Engineering Examination Questions With
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant Download Pdf
1. A steady-flow process occurs in a heat exchanger. Which principle
is primarily used to determine the heat transferred between
fluids?
A. Boyle’s Law
B. Bernoulli’s Equation
C. First Law of Thermodynamics
D. Raoult’s Law
Rationale: The First Law of Thermodynamics expresses conservation of
energy. In a heat exchanger operating at steady state, the energy
gained by one fluid equals the energy lost by the other, making this
law fundamental for heat-transfer calculations.
2. Which dimensionless number represents the ratio of inertial
forces to viscous forces in fluid flow?
,A. Prandtl Number
B. Schmidt Number
C. Nusselt Number
D. Reynolds Number
Rationale: The Reynolds Number is used to predict flow regimes. Low
values indicate laminar flow, while high values indicate turbulent flow.
It compares inertial and viscous forces within a fluid.
3. In distillation, the minimum number of theoretical stages is
commonly determined using:
A. Antoine Equation
B. Fenske Equation
C. Darcy Equation
D. Arrhenius Equation
Rationale: The Fenske Equation estimates the minimum number of
equilibrium stages required for a specified separation at total reflux,
making it a foundational design relationship in distillation.
4. The ideal gas law is expressed as:
A. PV = mRT²
B. PV = nRT
,C. P = ρRT²
D. PV² = nRT
Rationale: The ideal gas law relates pressure, volume, temperature,
and number of moles. It is widely used for gases under conditions
where intermolecular interactions are negligible.
5. Which type of reactor assumes complete mixing throughout the
vessel?
A. Plug Flow Reactor
B. Batch Reactor
C. Packed Bed Reactor
D. Continuous Stirred Tank Reactor (CSTR)
Rationale: A CSTR is assumed to be perfectly mixed, resulting in
uniform composition and temperature throughout the reactor volume.
6. Heat transfer by electromagnetic waves is called:
A. Conduction
B. Convection
C. Diffusion
D. Radiation
, Rationale: Radiation transfers energy through electromagnetic waves
and does not require a material medium, unlike conduction and
convection.
7. The unit of dynamic viscosity in SI units is:
A. N/m
B. J/kg
C. Pa·s
D. W/m²
Rationale: Dynamic viscosity measures resistance to flow and is
expressed in pascal-seconds (Pa·s), equivalent to kg/(m·s).
8. Which law describes diffusion flux proportional to concentration
gradient?
A. Newton’s Law
B. Fourier’s Law
C. Henry’s Law
D. Fick’s First Law
Rationale: Fick’s First Law states that mass transfer occurs from
regions of high concentration to low concentration at a rate
proportional to the concentration gradient.
Engineering Examination Questions With
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant Download Pdf
1. A steady-flow process occurs in a heat exchanger. Which principle
is primarily used to determine the heat transferred between
fluids?
A. Boyle’s Law
B. Bernoulli’s Equation
C. First Law of Thermodynamics
D. Raoult’s Law
Rationale: The First Law of Thermodynamics expresses conservation of
energy. In a heat exchanger operating at steady state, the energy
gained by one fluid equals the energy lost by the other, making this
law fundamental for heat-transfer calculations.
2. Which dimensionless number represents the ratio of inertial
forces to viscous forces in fluid flow?
,A. Prandtl Number
B. Schmidt Number
C. Nusselt Number
D. Reynolds Number
Rationale: The Reynolds Number is used to predict flow regimes. Low
values indicate laminar flow, while high values indicate turbulent flow.
It compares inertial and viscous forces within a fluid.
3. In distillation, the minimum number of theoretical stages is
commonly determined using:
A. Antoine Equation
B. Fenske Equation
C. Darcy Equation
D. Arrhenius Equation
Rationale: The Fenske Equation estimates the minimum number of
equilibrium stages required for a specified separation at total reflux,
making it a foundational design relationship in distillation.
4. The ideal gas law is expressed as:
A. PV = mRT²
B. PV = nRT
,C. P = ρRT²
D. PV² = nRT
Rationale: The ideal gas law relates pressure, volume, temperature,
and number of moles. It is widely used for gases under conditions
where intermolecular interactions are negligible.
5. Which type of reactor assumes complete mixing throughout the
vessel?
A. Plug Flow Reactor
B. Batch Reactor
C. Packed Bed Reactor
D. Continuous Stirred Tank Reactor (CSTR)
Rationale: A CSTR is assumed to be perfectly mixed, resulting in
uniform composition and temperature throughout the reactor volume.
6. Heat transfer by electromagnetic waves is called:
A. Conduction
B. Convection
C. Diffusion
D. Radiation
, Rationale: Radiation transfers energy through electromagnetic waves
and does not require a material medium, unlike conduction and
convection.
7. The unit of dynamic viscosity in SI units is:
A. N/m
B. J/kg
C. Pa·s
D. W/m²
Rationale: Dynamic viscosity measures resistance to flow and is
expressed in pascal-seconds (Pa·s), equivalent to kg/(m·s).
8. Which law describes diffusion flux proportional to concentration
gradient?
A. Newton’s Law
B. Fourier’s Law
C. Henry’s Law
D. Fick’s First Law
Rationale: Fick’s First Law states that mass transfer occurs from
regions of high concentration to low concentration at a rate
proportional to the concentration gradient.
