Q12 - Individual pyrrole molecules

[jas770]

This question is arguably incomprehensible. Could someone explain it?

[ManhattanPrepLSAT2]

This is a very difficult argument (and, by the way, for this type of question, your goal, as you read, shouldn't necessarily be to try and absorb everything - I know I couldn't).

Here's an analogous argument that might help:

Imagine that pyrrole molecules are people,

and polypyrroles are groups of people,

and zeolite are bars.

Here's how the argument might read with these substitutions:

Something people come together and hang out in groups. When people are around bars, and if decide to hang out in groups, they will do so either inside the bar, or outside on the patio. When the bar changes its sign from yellow to black, it means that there is a group hanging out at the bar.

Here's the equivalent conclusion:

The bar just changed the sign from yellow to black, and there are no groups hanging out on the patio.

What can we infer?

If the bar changed the sign color from yellow to black, it means a group must be hanging out there. If the group isn't hanging out outside, it must be inside.

Back to our LSAT problem, we know that there must be polyprroles inside, because we've been told there are none outside.

Armed with this information, we can see that (C) must be correct.

Hope that is helpful. Please feel free to follow up with any questions.

[cvfh17]

why B is incorrect?? thanks. hard question there is any special strategy to deal with these kind of dense information?

[sportsfan8491]

This is a very challenging question and I think the best strategy to attack this problem would be to pay close attention to the "or" statements and to understand exactly what they mean and what they are saying, as they are important for ruling out the incorrect choices and validating the correct choice. I read them twice to ensure that I saw the processes in the second sentence were mutually exclusive. Here is what I think about the answers:

A) is wrong for two reasons. The first reason is that the polypyrroles (PP) would have formed IN and NOT ON the zeolite - this can be obtained from the final sentence. It's amazing what the addition of one word ("ON") in a sentence can do to make it a wrong answer. Even if this subtle nuance was missed, you would be able to rule out this answer because it says "before", however, if the PP formed before, then the color would have already changed prior to the interaction of the molecules and we are told that the color changed after.

B) is wrong, but I must admit that this is a VERY tricky answer choice. It boils down to reading the second sentence extremely carefully (and correctly for that matter) and understanding what the "or" statement really means. We are told that LUMPS are formed on the outside while DELICATE CHAINS are formed within the zeolite. Thus, there are 2 processes by which PP form and they are mutually exclusive processes (those sneaky test writers!). The last sentence tells us that nothing formed on the outside, so it must have been on the inside, which would mean it would have been "DELICATE CHAINS" and not "LUMPS". Another reason I ruled out this answer choice was because of my thought process: it said that the lumps attaching was responsible for the color change, but do we actually know what caused the color to change? My thinking was that if anything was responsible for the color change, then it would be the interaction of the two molecules and not necessarily the lumps attaching and then I saw my first point that it must have been inside, so I realized LUMPS could not have been a plausible option.

C) IS CORRECT because we are told the color changed when the interaction occurred and we are further told it was not on the outer surface, which leads to the deduction that it must have been inside the zeolite. So, some pyrrole must have formed PP chains (the test writers surreptitiously exclude "delicate" to further hide this as the right answer) or else the observed phenomenon (color changing) would not make any sense.

D) is wrong because it contradicts the information we are given above, as some pyrrole must have attached to form PP in delicate chains within the zeolite. Remember that we are told the colour changed, so the interaction must have occurred, just not on the outside of the zeolite (i.e. on the outer surface).

E) is wrong for two reasons. The first reason it is wrong is because we cannot determine the quantity that reached the inner channels. It might have been a little or it might have been a lot, but we cannot validate this from the information we are provided. My second reason for ruling out this answer was because we know that some must have reached the inner channels and formed delicate chains, but the addition of "if any" implies that potentially none actually did reach or even form PP, but we know it did because the color changed. Thus, I think this answer, albeit subtly, contradicts the information we are given because of the "if any" statement.

I hope this explanation helps.

[csta5315]

The language in this problem is difficult to get around, but a good way to attack this (like Mike Kim said) was to imagine that each of these terms are something else, whatever is familiar to you that will make the passage much easier to interpret.

We know for a fact that polypyrroles are formed because the "yellow zeolite from of any pyrrole was submerged in dissolved pyrrole" and the zeolite turned black. So we know that it picked up some of the pyrrole BUT we do not see any pyrrole on the zeolite.

These could have formed from two ways :

1. they are in lumps at the end of the zeolite
OR
2. they are in a chain within the zeolites channels so here, we wouldn't even get a chance to be able to see the polypyrroles.

That is why C is the correct answer - we know that at least some of the pyrrole in which the zeolite submerged formed from the polypyrrole chains.

I hope this helps!!!