BR Chem - Is this ambiguous wording, or my mistake?

[Fortify]

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Menthol and camphor do not dissociate once in
solution. If an impurity were chosen that can dissociate
into two particles in solution, how would the freezing
point be affected?

A . The freezing point would decrease by twice as much
as expected, if the impurity did not dissociate
B. The freezing point would decrease by as much
expected, if the impurity did not dissociate



The comma halfway through the sentence threw me off. I answered B, because my interpretation was "The freezing point would decrease as expected if the impurity which could dissociate, didn't" because the comma splits the sentence into two clauses and implies a conditional if statement

I did consider that the correct answer was A. In this case, the meaning of the answer is "The freezing point would decrease by twice as much as it would without the impurity"

Did I interpret this wrong or is it a grammatical mistake in the text?

 

[Majik]

Menthol and camphor do not dissociate once in
solution. If an impurity were chosen that can dissociate
into two particles in solution, how would the freezing
point be affected?

A . The freezing point would decrease by twice as much
as expected, if the impurity did not dissociate
B. The freezing point would decrease by as much
expected, if the impurity did not dissociate



The comma halfway through the sentence threw me off. I answered B, because my interpretation was "The freezing point would decrease as expected if the impurity which could dissociate, didn't" because the comma splits the sentence into two clauses and implies a conditional if statement

I did consider that the correct answer was A. In this case, the meaning of the answer is "The freezing point would decrease by twice as much as it would without the impurity"

Did I interpret this wrong or is it a grammatical mistake in the text?

I agree, the wording is strange. The question tells you the impurity dissociates into two particles, which would mean van't hoff factor equals 2. This would double the freezing point depression. However, the answer choices are essentially saying, what would happen if the impurity didn't dissociate. If that's the case, van't hoff factor would equal 1 (which is half as less than we expect it to be). Therefore, the experimenter would mistakenly assume the freezing point dropped twice as much. The reason why B is wrong is because the freezing point did not drop by as much as expected since the answer choices explicitly state that the impurity didn't fully dissociate. Does that make sense? I admit, I initially chose B as well, but I understand why it's wrong now.

 

[Fortify]

I agree, the wording is strange. The question tells you the impurity dissociates into two particles, which would mean van't hoff factor equals 2. This would double the freezing point depression. However, the answer choices are essentially saying, what would happen if the impurity didn't dissociate. If that's the case, van't hoff factor would equal 1 (which is half as less than we expect it to be). Therefore, the experimenter would mistakenly assume the freezing point dropped twice as much. The reason why B is wrong is because the freezing point did not drop by as much as expected since the answer choices explicitly state that the impurity didn't fully dissociate. Does that make sense? I admit, I initially chose B as well, but I understand why it's wrong now.

Right, the answer stems imply the correct answer should be C, half as much, as we'd expect it to dissociate but it doesn't, so we'll have half the freezing point change.

So B is wrong either way, but as written, the correct answer SHOULD be C

 

[geeyouknit]

Menthol and camphor do not dissociate once in
solution. If an impurity were chosen that can dissociate
into two particles in solution, how would the freezing
point be affected?

A . The freezing point would decrease by twice as much
as expected, if the impurity did not dissociate
B. The freezing point would decrease by as much
expected, if the impurity did not dissociate



The comma halfway through the sentence threw me off. I answered B, because my interpretation was "The freezing point would decrease as expected if the impurity which could dissociate, didn't" because the comma splits the sentence into two clauses and implies a conditional if statement

I did consider that the correct answer was A. In this case, the meaning of the answer is "The freezing point would decrease by twice as much as it would without the impurity"

Did I interpret this wrong or is it a grammatical mistake in the text?

To me, the commas are typos, or just poorly placed. For both options, they seem to be saying that if the impurity AB did dissociate into A and B, how would the change in temp compare to the expected change of AB not dissociating. The expected thing is if it didn't dissociate. Since it did, the change in temp would be twice as much as expected.

 

[riddler]

To me, the commas are typos, or just poorly placed. For both options, they seem to be saying that if the impurity AB did dissociate into A and B, how would the change in temp compare to the expected change of AB not dissociating. The expected thing is if it didn't dissociate. Since it did, the change in temp would be twice as much as expected.

Hm. To me, it seems to be the other way around. The question stem tells us that the impurity CAN dissociate (which I assume to mean it does dissociate). I thought the answer choices, then, were saying that in the event that the impurity DOES NOT dissociate (while, from the question stem, we expected it to dissociate), how would the freezing point change? It would be half as much as expected, since we expected, from the question stem, that the impurity would dissociate and depress the freezing point twice as much as if it did not dissociate.