Free Chemical Reaction Engineering MCQs with Answers
395 Chemical Reaction Engineering MCQs from Chemical Engineering, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
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- A. Solutions
- B. Liquid state only
- C. Solid state only
- D. Any state
Explanation: Ionic reactions involve ions moving and reacting in a medium, so they are commonly studied in aqueous or other liquid solutions.
Correct answer: Solutions- A. Increases
- B. Decreases
- C. Remain unaffected
- D. Increases linearly with temperature
Explanation: An endothermic reaction absorbs heat, so lowering the temperature shifts equilibrium toward the reactants according to Le Chatelier’s…
Correct answer: Decreases- A. Hydrogenation of oils
- B. Alkylation of hydrocarbons
- C. Gas phase oxidation of SO2 in chamber process
- D. None of these
Explanation: Sulphuric acid provides acidic sites that promote the formation of alkylated hydrocarbons from an olefin and an isoparaffin.
Correct answer: Alkylation of hydrocarbons- A. Most suitable for a second order reaction
- B. Most suitable for a reversible reaction
- C. Completely self-supporting in its thermal energy requirements
- D. Isothermal in nature
Explanation: An autothermal reactor obtains the heat required for an endothermic reaction, or removes the heat generated by an exothermic reaction…
Correct answer: Completely self-supporting in its thermal energy requirements- A. Increasing the concentration of one of the reactants
- B. None of these
- C. Removal of at least one of the products at regular interval
- D. Increasing the concentration of one or more of the products
Explanation: Adding a product increases the reaction quotient, so the equilibrium shifts toward reactants to consume some of that product.
Correct answer: Increasing the concentration of one or more of the products- A. -rA = (k . PA . PB)/(1 + KAPB + KBPB . KPPP)
- B. -rA = (k . PA
- C. 2 - k1PP)/(1 + KAPA + KPPP)
- D. -rA = (k . PA . PB)/(1 + KAPA + KPPP)
- E. -rA = (k . PA . PB)/(1 + KAPA)
Explanation: For the Rideal mechanism, one reactant is adsorbed while the other reacts directly from the gas phase, giving a rate proportional to PA…
Correct answer: -rA = (k . PA . PB)/(1 + KAPA + KPPP)- A. Batch reactor is preferred over a single CSTR for high yield
- B. Tubular reactor is preferred over a single CSTR for high yield
- C. Both A. and B.
- D. Single CSTR is the most suitable
Explanation: When the desired reaction has the higher order, high reactant concentration improves its rate relative to the undesired reaction.
Correct answer: Both A. and B.108. A first order reaction requires two unequal sized CSTR. Which of the following gives higher yield ?
- A. Large reactor followed by smaller one
- B. Smaller reactor followed by larger one
- C. Data insufficient, can't be predicted
- D. Either of the arrangement A. or B. will give the same yield
Explanation: For a first-order reaction in CSTRs, the overall conversion depends on the sum of the reactor volumes divided by the flow rate, not on…
Correct answer: Either of the arrangement A. or B. will give the same yield- A. 256
- B. 512
- C. 112
- D. 612
Explanation: The temperature rises by 90°C, which equals nine 10°C intervals. Doubling nine times gives 2^9 = 512, so the rate becomes 512 times its…
Correct answer: 512- A. > 1
- B. 1
- C. < 1
- D. 0
Explanation: With constant density, the volumetric flow rate does not change through the reactor, so space time V divided by flow rate equals the mean…
Correct answer: 1- A. Catalytic
- B. Photochemical
- C. Autocatalytic
- D. None of these
Explanation: A reaction is autocatalytic when one of its products catalyses the same reaction, causing the reaction rate to depend partly on product…
Correct answer: Autocatalytic- A. None of these
- B. Useful volume of the tank
- C. Diameter of the reactor
- D. Time
Explanation: In a batch reactor, material is charged and then allowed to react without continuous feed or withdrawal, so time is the independent…
Correct answer: Time- A. Equals
- B. Is smaller than
- C. Is greater than
- D. Can be either greater or smaller than (depends on the type of reaction)
Explanation: When the limiting reactant is completely consumed, the amount used as the basis for operational yield is the same stoichiometric reactant…
Correct answer: Equals- A. Feed rate
- B. Reactor volume
- C. All A., B. and C.
- D. Extent of reaction
Explanation: Reactor performance balances connect the reaction rate with the feed rate and reactor volume, while the extent of reaction expresses the…
Correct answer: All A., B. and C.- A. There is no mixing in longitudinal direction
- B. Mixing takes place in radial direction
- C. There is a uniform velocity across the radius
- D. All A., B. and C.
Explanation: An ideal tubular-flow reactor has plug flow: no longitudinal or axial mixing, complete radial mixing, and a uniform velocity profile…
Correct answer: All A., B. and C.- A. Non-adiabatic
- B. Isothermal
- C. Adiabatic
- D. None of these
Explanation: An adiabatic reactor has no heat exchange, while an isothermal reactor maintains constant temperature.
Correct answer: Non-adiabatic- A. Decreases
- B. Increases
- C. Remain same
- D. Becomes infinite
Explanation: A catalyst provides an alternative pathway with lower activation energy, increasing the forward reaction rate constant at a given…
Correct answer: Increases- A. Batch
- B. Tubular flow
- C. Stirred tank
- D. Fixed bed
Explanation: A stirred-tank reactor provides continuous mixing and effective heat removal, making it suitable for nearly isothermal liquid-phase…
Correct answer: Stirred tank- A. 8
- B. 1/8
- C. 16
- D. 1/16
Explanation: Reducing the reactor volume to one-fourth increases each gas concentration fourfold when the number of moles is unchanged.
Correct answer: 16- A. Pressure has no effect
- B. Backward reaction is favoured
- C. Forward reaction is favoured
- D. None of these
Explanation: The reaction has five total moles of gaseous reactants and five total moles of gaseous products.
Correct answer: Pressure has no effect