Parramatta Library HSC Chemistry Trial Discussion (2 Viewers)

zhertec

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Gonna attempt to MC of this paper now, brb in 20 minutes :3

P.S. strawberrye, you should've promoted this event more cause I didn't hear/missed out on it! QQ
 

zhertec

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Ok I'm back, did pretty bad...lol

Q3 - incorrect due to failure of analysing properly lol
Q7 - was iffy on this one, mind if someone explain?
Q10 - lol missed out on the third isomer was, was switching between A and C constantly due to time constraints xD
Q11 - read the question wrong, read as decreasing, instead it should be increasing concentration (hopefully will not make the same mistake in the exam again -.-)
Q16 - lack of knowledge on what tartaric acid was (to me sounded pretty dangerous compared to the others) nevertheless it was either A or C, though I picked the wrong one xD
Q19 - Hmm this one, D was a pretty general statement that isnt totally incorrect is it?

P.S. probably one of, if not the hardest, MCQ I've experienced. Good work setting it up :3
 
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strawberrye

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Gonna attempt to MC of this paper now, brb in 20 minutes :3

P.S. strawberrye, you should've promoted this event more cause I didn't hear/missed out on it! QQ
I have promoted this event as much as I could. I actually gave a whole months notice on BOS, and parra library has been promoting it very vigorously as well:) perhaps you can give me some suggestions on how I can better promote these events in the future:)
 

zhertec

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I have promoted this event as much as I could. I actually gave a whole months notice on BOS, and parra library has been promoting it very vigorously as well:) perhaps you can give me some suggestions on how I can better promote these events in the future:)
Giant banner that completely replaces the BOS title page, and a really annoying popup informing you about the event WHENEVER you click on a link :3 lol jks probably needed more of the general community's interest (try incentives like cookies :3). Though I think I might have seen this post, I could have misread it as like a tutoring.revision. In that case, my bad xD
 

M_Francis

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All answers to the exams are up now, if you have any questions feel free to ask:)
For qn 7, all answers are correct. all of them involve a proton exchange
In C, The following Bronsted-Lowry eqns are put in one eqn:
N3- + H2O --> NH^2- + OH- (cbb states)
NH^2- + H2O --> NH2^- + OH- (cbb states)
NH2^- + H2O --> NH3 + OH- (cbb states)

When they are combined these eqns give u the eqn in C


Also, the answer for Qn 11 should be A/C NOT B/D


What do you think the B6 cut off for this paper would be?



Please correct me if i'm wrong Strawberry. BUT thank you soooooo much on such a brain-stimulating paper!

BUMP! (even though i dont know wth this means)
 

strawberrye

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For qn 7, all answers are correct. all of them involve a proton exchange
In C, The following Bronsted-Lowry eqns are put in one eqn:
N3- + H2O --> NH^2- + OH- (cbb states)
NH^2- + H2O --> NH2^- + OH- (cbb states)
NH2^- + H2O --> NH3 + OH- (cbb states)

When they are combined these eqns give u the eqn in C


Also, the answer for Qn 11 should be A/C NOT B/D


What do you think the B6 cut off for this paper would be?



Please correct me if i'm wrong Strawberry. BUT thank you soooooo much on such a brain-stimulating paper!

BUMP! (even though i dont know wth this means)
Very nice observation for question 7, however, I was looking for the least correct answer, and in this context, it was the equation you have mentioned, technically it is not a proton exchange, but several successive steps of proton exchanges, as such, in this case, technically it is not a Bronsted Lowry equation in the dominant understanding of it-as in involving conjugate acid and bases in the one equation. The question is actually really tricky for people who knows the chemistry:) but with your explanation, I will be prepared to give you the mark.

Can you explain to me why question 11 should be A/C and not B/D by Le Chatelier's principle? (because if you apply the principle correctly, only B/D results in decrease of carbon dioxide concentration).

I am not sure what the band 6 cut off for the paper would be, but I would say around 53/75:) How did you find the other questions? Thanks for your feedback, it makes all those tedious hours working on the paper worth it:) Literally took me more than 20 hours of work, the process was extremely time consuming, needed to read through loads of other past papers to make sure I don't have too many same questions, needed to review a lot of textbooks to ensure I don't ask questions outside the scope of the syllabus, being a teacher, or pretending to be one, is really tough:)
 

M_Francis

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Very nice observation for question 7, however, I was looking for the least correct answer, and in this context, it was the equation you have mentioned, technically it is not a proton exchange, but several successive steps of proton exchanges, as such, in this case, technically it is not a Bronsted Lowry equation in the dominant understanding of it-as in involving conjugate acid and bases in the one equation. The question is actually really tricky for people who knows the chemistry:) but with your explanation, I will be prepared to give you the mark.

Can you explain to me why question 11 should be A/C and not B/D by Le Chatelier's principle? (because if you apply the principle correctly, only B/D results in decrease of carbon dioxide concentration).

I am not sure what the band 6 cut off for the paper would be, but I would say around 53/75:) How did you find the other questions? Thanks for your feedback, it makes all those tedious hours working on the paper worth it:) Literally took me more than 20 hours of work, the process was extremely time consuming, needed to read through loads of other past papers to make sure I don't have too many same questions, needed to review a lot of textbooks to ensure I don't ask questions outside the scope of the syllabus, being a teacher, or pretending to be one, is really tough:)

Ohh okay thanks heaps then

I know B/D result in a decrease in CO2 concentration but at t=3 there is actually an increase in concentration. So it should be A/C. Right?


The other questions were really good. Nice work, you nailed it!
 

strawberrye

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Bump - Chem in 3 days
Thanks for the BUMP:)

To everyone:)
Now is your last chance to ask questions:) Go and take this opportunity to see where HSC Chemistry can take you:) May you all define your HSC results and never let your results define you:)
 

M_Francis

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Thanks for the BUMP:)

To everyone:)
Now is your last chance to ask questions:) Go and take this opportunity to see where HSC Chemistry can take you:) May you all define your HSC results and never let your results define you:)
Can you reply to my previous query?

"I know B/D result in a decrease in CO2 concentration but at t=3 there is actually an increase in concentration. So it should be A/C. Right?"
 

M_Francis

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Thanks for the BUMP:)

To everyone:)
Now is your last chance to ask questions:) Go and take this opportunity to see where HSC Chemistry can take you:) May you all define your HSC results and never let your results define you:)

Am I right?
 
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strawberrye

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Wow. Are you really ignoring me because i'm right?
I am not. Its just I have been really busy recently. Try not to take other peoples action personally without adequate knowledge otherwise its very easy to get upset (I am saying this from personal experience), the best answer is actually B because when you increase pressure, there is an instantaneous decrease in volume, resulting in momentary increase in concentration of all gaseous species, including carbon dioxide before lechateliers principle reestablish a new equilibrium by shifting it to the right to minimise change. I have also been quite tired so it is hard to answer questions as quickly as you would have liked to, I seek your understanding and I hope you understand my explanation:)
 

M_Francis

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I am not. Its just I have been really busy recently. Try not to take other peoples action personally without adequate knowledge otherwise its very easy to get upset (I am saying this from personal experience), the best answer is actually B because when you increase pressure, there is an instantaneous decrease in volume, resulting in momentary increase in concentration of all gaseous species, including carbon dioxide before lechateliers principle reestablish a new equilibrium by shifting it to the right to minimise change. I have also been quite tired so it is hard to answer questions as quickly as you would have liked to, I seek your understanding and I hope you understand my explanation:)
Your explanation makes a lot of sense, thanks for that. My chem teacher only taught my class half of the syllabus which is why i couldnt recognise this.

Its fine dw about it. Thanks heaps once again
 

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