Chemical Engineering Principles MCQs with Answers
Which of the following is not a unit operation in chemical engineering?
a) Distillation
b) Filtration
c) Mixing
d) Stoichiometry
Answer: d) Stoichiometry
The McCabe-Thiele method is used for the design of:
a) Heat exchangers
b) Reactors
c) Distillation columns
d) Pumps
Answer: c) Distillation columns
The term “creep” is associated with the:
a) Corrosion of metals
b) Flow of fluids
c) Deformation of solids under constant load
d) Combustion of fuels
Answer: c) Deformation of solids under constant load
The PFD (Process Flow Diagram) is a schematic representation of a:
a) Heat exchanger
b) Chemical reaction
c) Process plant
d) Fluid flow pattern
Answer: c) Process plant
Which of the following is an example of a steady-state process?
a) Filling a tank with water
b) Boiling water in a kettle
c) Heating a room with a radiator
d) Charging a battery
Answer: c) Heating a room with a radiator
The principle of conservation of mass is based on:
a) The first law of thermodynamics
b) The second law of thermodynamics
c) The law of conservation of energy
d) The law of conservation of mass
Answer: d) The law of conservation of mass
The term “viscosity” refers to a fluid’s resistance to:
a) Heat transfer
b) Mass transfer
c) Flow
d) Reaction kinetics
Answer: c) Flow
The term “diffusion” is associated with the:
a) Mixing of gases
b) Mixing of liquids
c) Transfer of heat
d) Transfer of mass
Answer: d) Transfer of mass
Which of the following is not a primary variable in thermodynamics?
a) Pressure
b) Temperature
c) Volume
d) Enthalpy
Answer: d) Enthalpy
The term “molar flow rate” refers to the:
a) Mass flow rate per unit volume
b) Mass flow rate per mole
c) Volume flow rate per unit volume
d) Volume flow rate per mole
Answer: b) Mass flow rate per mole
The Nusselt number is used to characterize:
a) Heat transfer in laminar flow
b) Heat transfer in turbulent flow
c) Mass transfer in laminar flow
d) Mass transfer in turbulent flow
Answer: b) Heat transfer in turbulent flow
The term “Reynolds number” is used to determine the flow regime in a fluid system and is defined as the ratio of:
a) Inertial forces to gravitational forces
b) Viscous forces to gravitational forces
c) Inertial forces to viscous forces
d) Volumetric flow rate to surface area
Answer: c) Inertial forces to viscous forces
The term “turbulence” refers to:
a) Unsteady flow
b) Chaotic flow patterns
c) Low flow rate
d) High viscosity
Answer: b) Chaotic flow patterns
The term “stoichiometry” is concerned with the:
a) Flow of fluids
b) Transfer of heat
c) Transfer of mass
d) Quantitative relationships between reactants and products in a chemical reaction
Answer: d) Quantitative relationships between reactants and products in a chemical reaction
The term “equilibrium” refers to a state where:
a) The system is at rest
b) The system is in balance
c) The system is at constant temperature
d) The system is at constant pressure
Answer: b) The system is in balance
The term “adsorption” refers to the:
a) Reaction between two chemicals
b) Transfer of heat between two fluids
c) Transfer of mass between two phases
d) Adhesion of molecules to a surface
Answer: d) Adhesion of molecules to a surface
The term “catalyst” refers to a substance that:
a) Speeds up a chemical reaction without being consumed in the process
b) Slows down a chemical reaction without being consumed in the process
c) Converts a solid into a gas
d) Converts a liquid into a solid
Answer: a) Speeds up a chemical reaction without being consumed in the process
The term “reactor” refers to a vessel or system in which:
a) Chemical reactions take place
b) Heat transfer occurs
c) Mass transfer occurs
d) Fluid flow is controlled
Answer: a) Chemical reactions take place
The term “residence time” in a reactor refers to:
a) The time required for a reactant to complete a single pass through the reactor
b) The time required for a reactant to react completely
c) The time required for a reactor to reach steady state
d) The time required for a reactor to cool down after a reaction
Answer: a) The time required for a reactant to complete a single pass through the reactor
The term “yield” in a chemical process refers to the:
a) Percentage of a desired product obtained from a reaction
b) Percentage of reactants converted into products
c) Percentage of impurities in a product
d) Percentage of heat loss in a process
Answer: a) Percentage of a desired product obtained from a reaction
The term “mass transfer coefficient” is used to quantify the:
a) Rate of heat transfer
b) Rate of mass transfer
c) Rate of fluid flow
d) Rate of chemical reaction
Answer: b) Rate of mass transfer
The term “distillation” is a separation process based on the difference in:
a) Chemical composition
b) Physical properties
c) Pressure
d) Temperature
Answer: b) Physical properties
The term “absorption” is a separation process based on the:
a) Difference in boiling points
b) Difference in solubility
c) Difference in density
d) Difference in viscosity
Answer: b) Difference in solubility
The term “crystallization” is a separation process based on the difference in:
a) Boiling points
b) Melting points
c) Solubilities
d) Viscosities
Answer: c) Solubilities
The term “evaporation” is a separation process based on the difference in:
a) Boiling points
b) Melting points
c) Solubilities
d) Viscosities
Answer: a) Boiling points
The term “filtration” is a separation process based on the difference in:
a) Boiling points
b) Melting points
c) Particle size
d) Solubilities
Answer: c) Particle size
The term “heat exchanger” is a device used for:
a) Mixing fluids
b) Separating solids from liquids
c) Transferring heat between fluids
d) Catalyzing chemical reactions
Answer: c) Transferring heat between fluids
The term “pump” is a device used for:
a) Mixing fluids
b) Separating solids from liquids
c) Transferring heat between fluids
d) Increasing the pressure of a fluid
Answer: d) Increasing the pressure of a fluid
The term “compressor” is a device used for:
a) Mixing fluids
b) Separating solids from liquids
c) Transferring heat between fluids
d) Increasing the pressure of a gas
Answer: d) Increasing the pressure of a gas
The term “distillation column” is a device used for:
a) Mixing fluids
b) Separating solids from liquids
c) Transferring heat between fluids
d) Separating components of a liquid mixture based on boiling points
Answer: d) Separating components of a liquid mixture based on boiling points
The term “reactor vessel” is a device used for:
a) Mixing fluids
b) Separating solids from liquids
c) Transferring heat between fluids
d) Carrying out chemical reactions
Answer: d) Carrying out chemical reactions
The term “heat transfer coefficient” is a measure of:
a) The efficiency of a heat exchanger
b) The rate of heat transfer per unit area
c) The temperature difference across a heat exchanger
d) The thermal conductivity of a fluid
Answer: b) The rate of heat transfer per unit area
The term “viscous flow” refers to a fluid flow behavior characterized by:
a) High viscosity and low flow rate
b) Low viscosity and high flow rate
c) High viscosity and high flow rate
d) Low viscosity and low flow rate
Answer: a) High viscosity and low flow rate
The term “turbulent flow” refers to a fluid flow behavior characterized by:
a) Chaotic flow patterns and high Reynolds number
b) Smooth flow patterns and low Reynolds number
c) Chaotic flow patterns and low Reynolds number
d) Smooth flow patterns and high Reynolds number
Answer: a) Chaotic flow patterns and high Reynolds number
The term “Bernoulli’s equation” describes the relationship between:
a) Pressure and temperature in a fluid
b) Flow rate and pressure drop in a pipe
c) Viscosity and density of a fluid
d) Velocity and pressure in a fluid
Answer: d) Velocity and pressure in a fluid
The term “Newtonian fluid” refers to a fluid that exhibits:
a) Constant viscosity at different shear rates
b) Varying viscosity at different shear rates
c) High viscosity and low shear stress
d) Low viscosity and high shear stress
Answer: a) Constant viscosity at different shear rates
The term “non-Newtonian fluid” refers to a fluid that exhibits:
a) Constant viscosity at different shear rates
b) Varying viscosity at different shear rates
c) High viscosity and low shear stress
d) Low viscosity and high shear stress
Answer: b) Varying viscosity at different shear rates
The term “Reynolds transport theorem” is used to analyze:
a) Energy conservation in fluid systems
b) Mass conservation in fluid systems
c) Momentum conservation in fluid systems
d) Entropy generation in fluid systems
Answer: b) Mass conservation in fluid systems
The term “Hagen-Poiseuille equation” is used to describe:
a) Pressure drop in a pipe due to friction
b) Flow rate in a pipe
c) Heat transfer in a pipe
d) Mass transfer in a pipe
Answer: b) Flow rate in a pipe
The term “Darcy’s law” is used to describe:
a) Pressure drop in a pipe due to friction
b) Flow rate in a pipe
c) Heat transfer in a pipe
d) Mass transfer in a pipe
Answer: a) Pressure drop in a pipe due to friction
The term “heat capacity” refers to the amount of heat required to:
a) Change the temperature of a substance by a given amount
b) Change the pressure of a substance by a given amount
c) Change the phase of a substance from solid to liquid
d) Change the composition of a substance by a given amount
Answer: a) Change the temperature of a substance by a given amount
The term “heat of reaction” refers to the amount of heat released or absorbed during a:
a) Chemical reaction
b) Physical transformation
c) Phase change
d) Heat transfer process
Answer: a) Chemical reaction
The term “latent heat” refers to the heat required to:
a) Change the temperature of a substance
b) Change the pressure of a substance
c) Change the phase of a substance at constant temperature
d) Change the composition of a substance at constant temperature
Answer: c) Change the phase of a substance at constant temperature
The term “heat exchanger effectiveness” is a measure of:
a) The efficiency of a heat exchanger in transferring heat
b) The temperature difference across a heat exchanger
c) The pressure drop in a heat exchanger
d) The heat transfer coefficient of a fluid
Answer: a) The efficiency of a heat exchanger in transferring heat
The term “rate of reaction” refers to the:
a) Speed at which a chemical reaction occurs
b) Energy change during a chemical reaction
c) Equilibrium constant of a chemical reaction
d) Activation energy of a chemical reaction
Answer: a) Speed at which a chemical reaction occurs
The term “reaction rate constant” is a measure of:
a) The speed at which a chemical reaction occurs
b) The equilibrium constant of a chemical reaction
c) The activation energy of a chemical reaction
d) The rate of change of reactant concentration with time
Answer: a) The speed at which a chemical reaction occurs
The term “equilibrium constant” is a measure of:
a) The speed at which a chemical reaction occurs
b) The rate of change of reactant concentration with time
c) The stability of a chemical compound
d) The extent of a chemical reaction at equilibrium
Answer: d) The extent of a chemical reaction at equilibrium
The term “activation energy” refers to the:
a) Energy released or absorbed during a chemical reaction
b) Energy required to initiate a chemical reaction
c) Energy change associated with a phase change
d) Energy change associated with a heat transfer process
Answer: b) Energy required to initiate a chemical reaction
The term “catalytic activity” refers to the:
a) The ability of a catalyst to speed up a chemical reaction
b) The ability of a catalyst to slow down a chemical reaction
c) The ability of a catalyst to change phase
d) The ability of a catalyst to transfer heat
Answer: a) The ability of a catalyst to speed up a chemical reaction
The term “selectivity” in a chemical reaction refers to the:
a) The ability of a reactant to react with multiple products
b) The ability of a catalyst to catalyze multiple reactions
c) The ability of a reactant to react selectively with a specific product
d) The ability of a catalyst to be selective in its catalytic activity
Answer: c) The ability of a reactant to react selectively with a specific product
The term “residence time distribution” refers to the:
a) The distribution of residence times of reactants in a reactor
b) The distribution of residence times of products in a reactor
c) The distribution of residence times of fluids in a pipe
d) The distribution of residence times of particles in a sieve
Answer: a) The distribution of residence times of reactants in a reactor
The term “isothermal process” refers to a process that occurs at:
a) Constant temperature
b) Constant pressure
c) Constant volume
d) Constant entropy
Answer: a) Constant temperature
The term “adiabatic process” refers to a process that occurs with:
a) No heat transfer
b) No mass transfer
c) No phase change
d) No reaction
Answer: a) No heat transfer
The term “isobaric process” refers to a process that occurs at:
a) Constant temperature
b) Constant pressure
c) Constant volume
d) Constant entropy
Answer: b) Constant pressure
The term “isochoric process” refers to a process that occurs at:
a) Constant temperature
b) Constant pressure
c) Constant volume
d) Constant entropy
Answer: c) Constant volume
The term “ideal gas” refers to a gas that:
a) Exhibits ideal behavior at all conditions
b) Conforms to the ideal gas law under all conditions
c) Has a constant molar heat capacity at all temperatures
d) Does not interact with other gases or the surroundings
Answer: b) Conforms to the ideal gas law under all conditions
The term “real gas” refers to a gas that:
a) Exhibits non-ideal behavior at all conditions
b) Deviates from the ideal gas law under certain conditions
c) Has a variable molar heat capacity at different temperatures
d) Interacts with other gases or the surroundings
Answer: d) Interacts with other gases or the surroundings
The term “critical point” refers to the conditions at which a substance:
a) Changes phase from liquid to gas
b) Changes phase from solid to liquid
c) Exhibits maximum density
d) Exhibits the highest temperature and pressure at which it can exist as a vapor
Answer: d) Exhibits the highest temperature and pressure at which it can exist as a vapor
The term “triple point” refers to the conditions at which a substance:
a) Changes phase from liquid to gas
b) Changes phase from solid to liquid
c) Exhibits maximum density
d) Exists in equilibrium as solid, liquid, and vapor
Answer: d) Exists in equilibrium as solid, liquid, and vapor
The term “vapor pressure” refers to the pressure exerted by a:
a) Solid at its melting point
b) Liquid at its boiling point
c) Gas at its critical point
d) Solution at its solubility limit
Answer: b) Liquid at its boiling point
The term “flash distillation” is a separation process based on:
a) Differences in boiling points of components
b) Differences in solubilities of components
c) Differences in vapor pressures of components
d) Differences in densities of components
Answer: c) Differences in vapor pressures of components
The term “cracking” refers to a chemical process in which:
a) Large hydrocarbon molecules are broken down into smaller ones
b) Small hydrocarbon molecules are polymerized into larger ones
c) Oxygen is added to hydrocarbons to form alcohols
d) Hydrocarbons are converted into solid carbon
Answer: a) Large hydrocarbon molecules are broken down into smaller ones
The term “polymerization” refers to a chemical process in which:
a) Large hydrocarbon molecules are broken down into smaller ones
b) Small hydrocarbon molecules are polymerized into larger ones
c) Oxygen is added to hydrocarbons to form alcohols
d) Hydrocarbons are converted into solid carbon
Answer: b) Small hydrocarbon molecules are polymerized into larger ones
The term “carbonization” refers to a process in which:
a) Large hydrocarbon molecules are broken down into smaller ones
b) Small hydrocarbon molecules are polymerized into larger ones
c) Oxygen is added to hydrocarbons to form alcohols
d) Hydrocarbons are converted into solid carbon
Answer: d) Hydrocarbons are converted into solid carbon
The term “distillation” is a separation process based on the difference in:
a) Chemical composition
b) Physical properties
c) Pressure
d) Temperature
Answer: b) Physical properties
The term “absorption” is a separation process based on the:
a) Difference in boiling points
b) Difference in solubility
c) Difference in density
d) Difference in viscosity
Answer: b) Difference in solubility
The term “crystallization” is a separation process based on the difference in:
a) Boiling points
b) Melting points
c) Solubilities
d) Viscosities
Answer: c) Solubilities
The term “evaporation” is a separation process based on the difference in:
a) Boiling points
b) Melting points
c) Solubilities
d) Viscosities
Answer: a) Boiling points
The term “filtration” is a separation process based on the difference in:
a) Boiling points
b) Melting points
c) Particle size
d) Solubilities
Answer: c) Particle size
The term “heat exchanger” is a device used for:
a) Mixing fluids
b) Separating solids from liquids
c) Transferring heat between fluids
d) Catalyzing chemical reactions
Answer: c) Transferring heat between fluids