Chemical Engineer Intern Certification
Exam Practice Questions And Correct
Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
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1. A chemical engineer is performing a material balance around a
continuous reactor operating at steady state. Which statement
correctly describes the relationship between input and output streams
when no accumulation occurs?
A. Input flow rate must always be greater than output flow rate
B. Output flow rate must always be greater than input flow rate
C. Total mass entering the system equals total mass leaving the system
D. Reaction systems cannot satisfy a steady-state balance
Answer: C. Total mass entering the system equals total mass leaving the
system
,Rationale: In a steady-state process with no accumulation, the
conservation of mass principle requires that the total mass entering a
system equals the total mass leaving the system, regardless of whether
chemical reactions occur.
2. A chemical engineer calculates the number of moles in a sample using
the molecular weight and mass of the substance. Which equation
correctly represents this calculation?
A. Moles = Mass × Molecular Weight
B. Moles = Mass ÷ Molecular Weight
C. Moles = Molecular Weight ÷ Mass
D. Moles = Mass + Molecular Weight
Answer: B. Moles = Mass ÷ Molecular Weight
Rationale: The number of moles is determined by dividing the mass of a
substance by its molecular weight, allowing conversion between mass-
based and molar quantities.
3. In a chemical process, the purpose of a degree-of-freedom analysis is
to determine:
A. The economic profitability of a plant
B. Whether the number of unknown variables can be solved using available
equations
,C. The reaction rate constant of a chemical reaction
D. The safety classification of equipment
Answer: B. Whether the number of unknown variables can be solved using
available equations
Rationale: Degree-of-freedom analysis compares the number of unknown
variables with the number of independent equations to determine whether
a process problem is solvable.
4. Which thermodynamic property is classified as an intensive property?
A. Mass
B. Volume
C. Temperature
D. Total enthalpy
Answer: C. Temperature
Rationale: Intensive properties do not depend on the amount of material
present. Temperature, pressure, and density are examples, whereas mass
and volume are extensive properties.
5. The first law of thermodynamics is primarily based on the principle of:
A. Conservation of energy
B. Conservation of momentum
, C. Conservation of entropy
D. Conservation of volume
Answer: A. Conservation of energy
Rationale: The first law states that energy cannot be created or destroyed
but can be transferred or converted from one form to another.
6. For an ideal gas, the relationship among pressure, volume,
temperature, and number of moles is described by:
A. Bernoulli’s equation
B. Fourier’s law
C. Ideal gas law
D. Fick’s law
Answer: C. Ideal gas law
Rationale: The ideal gas law, PV = nRT, relates pressure, volume,
temperature, and amount of gas for ideal gas behavior.
7. A process engineer increases the temperature of a liquid while
maintaining constant pressure. Which property is expected to
increase?
A. Density
B. Specific volume
Exam Practice Questions And Correct
Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
1. A chemical engineer is performing a material balance around a
continuous reactor operating at steady state. Which statement
correctly describes the relationship between input and output streams
when no accumulation occurs?
A. Input flow rate must always be greater than output flow rate
B. Output flow rate must always be greater than input flow rate
C. Total mass entering the system equals total mass leaving the system
D. Reaction systems cannot satisfy a steady-state balance
Answer: C. Total mass entering the system equals total mass leaving the
system
,Rationale: In a steady-state process with no accumulation, the
conservation of mass principle requires that the total mass entering a
system equals the total mass leaving the system, regardless of whether
chemical reactions occur.
2. A chemical engineer calculates the number of moles in a sample using
the molecular weight and mass of the substance. Which equation
correctly represents this calculation?
A. Moles = Mass × Molecular Weight
B. Moles = Mass ÷ Molecular Weight
C. Moles = Molecular Weight ÷ Mass
D. Moles = Mass + Molecular Weight
Answer: B. Moles = Mass ÷ Molecular Weight
Rationale: The number of moles is determined by dividing the mass of a
substance by its molecular weight, allowing conversion between mass-
based and molar quantities.
3. In a chemical process, the purpose of a degree-of-freedom analysis is
to determine:
A. The economic profitability of a plant
B. Whether the number of unknown variables can be solved using available
equations
,C. The reaction rate constant of a chemical reaction
D. The safety classification of equipment
Answer: B. Whether the number of unknown variables can be solved using
available equations
Rationale: Degree-of-freedom analysis compares the number of unknown
variables with the number of independent equations to determine whether
a process problem is solvable.
4. Which thermodynamic property is classified as an intensive property?
A. Mass
B. Volume
C. Temperature
D. Total enthalpy
Answer: C. Temperature
Rationale: Intensive properties do not depend on the amount of material
present. Temperature, pressure, and density are examples, whereas mass
and volume are extensive properties.
5. The first law of thermodynamics is primarily based on the principle of:
A. Conservation of energy
B. Conservation of momentum
, C. Conservation of entropy
D. Conservation of volume
Answer: A. Conservation of energy
Rationale: The first law states that energy cannot be created or destroyed
but can be transferred or converted from one form to another.
6. For an ideal gas, the relationship among pressure, volume,
temperature, and number of moles is described by:
A. Bernoulli’s equation
B. Fourier’s law
C. Ideal gas law
D. Fick’s law
Answer: C. Ideal gas law
Rationale: The ideal gas law, PV = nRT, relates pressure, volume,
temperature, and amount of gas for ideal gas behavior.
7. A process engineer increases the temperature of a liquid while
maintaining constant pressure. Which property is expected to
increase?
A. Density
B. Specific volume
