For acrylic, a clear rigid plastic, to be cast, fairly complex molecul

Question

For acrylic, a clear rigid plastic, to be cast, fairly complex molecules must be induced to link up, in a process called polymerization. Polymerization is exothermic; i.e., its net effect is that each time molecules link, a small quantity of heat is generated. In addition, the rate of linking speeds up as temperature increases.

Which of the following can be inferred from the passage above?

(A) The method used to trigger the process of polymerization is a sharp increase in the temperature of the surrounding air. 
(B) Unless the heat that results from the linking of molecules is drawn of promptly, there will be a heat buildup at an accelerating rate as acrylic is cast. 
(C) In the casting of thin sheets of acrylic, which lose heat quickly to the surrounding air, polymerization proceeds much faster than it does in the casting of thick pieces. 
(D) If air temperatures are kept steady when acrylic is cast, the rate at which the molecules link remains constant. 
(E) Once the process of polymerization has been induced, it cannot be slowed before all possible links among molecules have been formed.

nivi2084 · Answer

Option B can be clearly inferred from the passage.

shashank2019 · Answer

GMATNinja  can you please explain why answer B is right versus the rest, especially A

carcass · Answer

This is a marvelous CR, to be honest.

For acrylic, a clear rigid plastic, to be cast, fairly complex molecules  must be induced  to link up, in a process called polymerization.

Now, the process to obtain polymerization must be induced, which means from external sources we have to start it and then take control, sort of, of the same. A similar scenario takes in place during the process of nuclear reaction inside the nuclear plant. However, it is self-sufficient.

Polymerization is exothermic; i.e., its net effect is that each time molecules link, a small quantity of heat is generated. In addition, the rate of linking speeds up as temperature increases.

In this sentence, we do know that in the process a small heat is generated and that when the process speeds up more heat coming. However, we do not know if the process rolls up on its own or we must intervene

(A) The method used to trigger the process of polymerization  is a  sharp increase   in the temperature of the surrounding air.

From the very first sentence, we do NOT know if when we trigger the process to obtain the polymer, it has to be  sharp  in its start or less. we do know ONLY we have to pull the trigger.

I suppose from the second sentence that, without being an expert, only from what I read, that the process is self-sufficient to some extent, at least.

More probable than not that an ongoing process takes in place is understandable fo the last fact

the rate of linking speeds up as temperature increases.

Regards

sweetpineapple · Answer

Can someone explain why option D doesn't work?

Anandkrishna03 · Answer

Hey sweetpineapple In the argument, it is given that "rate of linking speeds up as temperature increases", but we do not know about what might happen when the temperature is constant. There might also be other possibilities that if the temperature is constant the linking speed decreases or if the temperature remains constant the reaction may not even occur. So, we cannot be sure of the outcome of what might happen if the tempearture is constant unless and until information about the same has been provided in the argument. I hope this clarifies your doubt.

Mavisdu1017 · Answer

Hello expert,
I was tangled with B and E, cuz for me they are the same meaning but only in different wording.
In B, (at an accelerating rate) = (cannot be slowed) in E. Since once the process of polymerization has been triggered, each time the linking of molecules generates heat, so the rate of linking will not be slowed, so why is E wrong?
Hope expert help, and thanks in advance.

PSKhore · Answer

The best inference from the passage is:  (B)  Unless the heat that results from the linking of molecules is drawn off promptly, there will be a heat buildup at an accelerating rate as acrylic is cast.

Explanation:  The passage states that polymerization is exothermic, meaning it generates heat, and that the reaction rate increases with temperature. This directly implies that without proper heat dissipation, the heat generated during polymerization will cause the reaction rate to increase further, leading to a buildup of heat.

Why other options are incorrect:

(A)  The method used to trigger the process of polymerization is a sharp increase in the temperature of the surrounding air. 
While the passage mentions that increasing temperature speeds up polymerization, it doesn't say that a sharp increase is the method used to trigger it. The passage implies that polymerization can be initiated in other ways, like adding a catalyst, and that the rate of the reaction is then influenced by temperature.

(C)  In the casting of thin sheets of acrylic, which lose heat quickly to the surrounding air, polymerization proceeds much faster than it does in the casting of thick pieces. 
This is incorrect because the opposite is true. If heat dissipates quickly, the reaction slows down. Thin sheets would lose heat more readily, so they would not experience the accelerated reaction rate that a thick piece would.

(D)  If air temperatures are kept steady when acrylic is cast, the rate at which the molecules link remains constant. 
This is incorrect. The passage states that temperature affects the rate of linking. While constant air temperature means no change in temperature, the initial heat generated by the polymerization reaction will still increase the temperature of the plastic itself, thus increasing the reaction rate.

(E)  Once the process of polymerization has been induced, it cannot be slowed before all possible links among molecules have been formed. 
This is incorrect. While the passage indicates that the reaction rate increases with temperature, it does not suggest that once it's started, you can't control it. You can control the temperature (and thus the reaction rate) with cooling, and therefore slow or stop the reaction.

Source: AI Overview

For acrylic, a clear rigid plastic, to be cast, fairly complex molecul

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For acrylic, a clear rigid plastic, to be cast, fairly complex molecul

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