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| One of the goals of the course is to have the readers further develop their critical thinking skills. One way to achieve this goal is through Socratic questioning. Throughout the course students will be asked to write questions on critical thinking drawing from information the Preface section B2. Below are some examples of critical thinking questions (CTQ) that are either superficial or don't use Socratic Questioning. |
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1. What specifically is the product?
While this question could be a CTQ from the clarification category, it is not a good critical thinking question because it is superficial and the information is about the product and is not relevant to solving for the conversion and reactor volumes as well as critiquing the answers.
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2. Is the reactor really tubular or does it have some bulges in it?
This is not a good critical thinking question because we know in Chapter 1 that even if the reactor varies in cross sectional area the conversion-volume relationship is the same.
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3. Other not so good critical thinking questions
Will this be on the exam?
What's the correct answers?
Why is there a "2" in this equation?
What are the units of this symbol?
While the last two questions are not CTQs, they may be valid questions
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4. Is the rate law expected to hold at a lower temperature?
This question is not a good CTQ because it is superficial and not sufficiently penetrating.
Better would be
Under what conditions might the activation energy and reaction order change in temperature. This question is a good CTQ because it explores the assumptions under which the rate law might change, such as in Langmuir Hinschelwood kinetics.
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5. What equations should I use to solve the problem?
This question is not a good CTQ.
A similar, but better question is,
What thought process led you to choose the CSTR equation for the case of constant volumetric flow rates?
This question asks to describe the assumptions needed to arrive at the CSTR equation.
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6. Do the experimental data taken to formulate the rate law justify the reaction order being in integer?
This is a good CTQ because it probes the reason of perhaps rounding a reaction order of 1.8 up to a second order reaction when the evidence from the data support an order of 1.8.
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7. What are the consequences of make the reaction order in integer?
This is a good CTQ because it probes implications and consequences.
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8. The liquid phase volumetric flow rate was at at 25 dm3/s giving as space time of 45 seconds. This flow rate is quite high. Do you feel this flow rate can be achieved in practice and that 90% conversion can be achieved?
This is a good CTQ because it challenges the questions perspective and view points from a practical standpoint (is υ0 = 25 dm3/s ) reasonable, and probes implications as to whether 90% conversion can be achieved because of perhaps poor mixing resulting from the high flow rates.
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9. Constant molar flow rates were assumed in the treatment of this question, how would your approach to this problem differ if this assumption were not valid? Assuming that the given reaction is highly exothermic, what is the advantage of using a semi-batch reactor for this process?
These questions are of the Socratic form because they probes implications and consequences of changing the conditions of the original problem. The student is required to understand the problem in its entirety rather than just memorizing the approach used for specific conditions.
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