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CSSA 2007 Chemistry Trial Examination thoughts (4 Viewers)

Halabys

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2opinion8d said:
it was indeed really challenging... not just those copy paste syllabus questions that we're all used to...

after the exam (in the car on the way home) i was like damn why didn't i talk about how australia has plently of sunshine and land for growing crops for ethanol production/ queesland/ sugarcane etc.... in the exam i just went on and on about hows its renewable etc... completely ignored "Australia"

for that calcium phosphate question i got something like 0.64% phosphorus???

For the K question i got 7. something

For that titration i got an abnormally low concentration... i was a bit sleepy during the exam and i got something like 0.09.... I think..

and yeah i put D for that MC 14... it clearly said oxygen atom. The oxygen atom and free radical are the same thing.
i got very similar results.....

hope ur right
 

Martyno1

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markymark1990 said:
I take that as a no then? Nobody able to help? It would be much appreciated. xx
"A Note from the Moderators:
We would love to hear how you went in your trials after you have completed them, but to keep it fair please keep in mind not to give out the actual questions from the papers as some students may do the same paper as you at a different date. If you wish to submit your trial questions/papers to the site please use the notes submission system or PM me with the questions and I will place them on the site after the trial period.

- Karen (Without Wings)"
 

wrxsti

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markymark1990 said:
I take that as a no then? Nobody able to help? It would be much appreciated. xx
i normally would help.... but how can we??? like we have to do the questions on the actual paper.... so we really cant send yaz the paper......

ill post up the paper when i get it back which should be 6 months after the HSC since my teacher is the sloweest marker and lazyest person ive ever seen (we only got 4 students in chemistry........)
 

markymark1990

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Martyno1 said:
"A Note from the Moderators:
We would love to hear how you went in your trials after you have completed them, but to keep it fair please keep in mind not to give out the actual questions from the papers as some students may do the same paper as you at a different date. If you wish to submit your trial questions/papers to the site please use the notes submission system or PM me with the questions and I will place them on the site after the trial period.

- Karen (Without Wings)"
Wow i didn't realise at all! How much i feel like an idiot right now! haha. I just hoped someone could help me in preventing my failure with my exam coming up. I want to at least pass one assessment task for chemistry this year...n i was hopin maybe this could be it. Any hints on what to study or anythin? Please feel free to email me if u can help me.
marky_mark1990@hotmail.com
Thanks!
 

wrxsti

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know a known Biopolymer, Hydration of Ethene to Ethanol. Fermentation of Ethanol, Why you need Reflux, Monitoring temperature for Haber Process, BOD (Biochemical Oxygen Demand), thats all i can remember sorry... and yer ders a simple titration question :)
 

markymark1990

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wrxsti said:
know a known Biopolymer, Hydration of Ethene to Ethanol. Fermentation of Ethanol, Why you need Reflux, Monitoring temperature for Haber Process, BOD (Biochemical Oxygen Demand), thats all i can remember sorry... and yer ders a simple titration question :)
Thank you so much! Helps me a heap! I appreciate it so much! Hopefully it'll be the first assessment i pass this year in chemistry. N it might be thanks to you so thanks you! xx
 

tehsky

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whats was the BOD question? i cant remmeber seeing it in the test :|
but yeh it wasnt that hard of a test...i think i got over 70% easily...well hopefully? x)
only thing that stumped me was the cfc's equations, i forgot em =[ oh and that phosohphorus question, noOoO clue what todo =O
 

2opinion8d

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I think the BOD question was something along the lines of describing the test for BOD and evaluate its effectiveness for control and monitoring eutrophication...

I'm not sure how many marks i'll get but i basically defined BOD and then described the test:
Using a DO sensor on day zero and then again after placing the sample of water in a brown capped bottle in the dark at 20C for 5 days. The BOD is the difference in the two DO values.

I then talked about how when algal blooms, present because of eutrophication, die, the decomposers use up oxygen in the water to in order to break them down... Thus water that has been plagued by algal blooms has a very high BOD. Therefore BOD can be used as an indicator for algal blooms and eutrophication as the higher the BOD the greater the extent of eutrophication.
I finished off by saying although its useful as a test for monitoring eutrophication it should not be used alone as high BOD's can be due to other factors such as sewage contamination. Therefore further tests to determine nitrogen and phosphate concentration of the water should be carried out.

Briefly, thats how I interpreted the question anyway, any one else get anything similar?

and Halaby's congrats on ur first post :)
 

wrxsti

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yer i did the same... pretty much word for word.... xcept i said it would be VERY suitable for Eutrophication and backed it up with some statements (in the evaluation at the end) ....... but seriosuly dats a stupid question to give 6 marks for.... :S
 

beentherdunthat

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wrxsti said:
yer i did the same... pretty much word for word.... xcept i said it would be VERY suitable for Eutrophication and backed it up with some statements (in the evaluation at the end) ....... but seriosuly dats a stupid question to give 6 marks for.... :S
:wave: Hahaha, Yeah aye??? That was just an unbalanced exam, I think I wrote like an article for that but concluded it quick coz what a boring question... hope we all do good though. :)
 

tehsky

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=S i so cant remember that inmy exam!
any cluee what question it was?
Maybe my school left it out...?
 

beentherdunthat

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The worst thing is missing out a question... last year my friend didn't see a WHOLE page in the options section in the bio hsc... *shivers* That is MY WORST FEAR...
 

tehsky

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yeahh...our paper had like 27/28 questions. im SURE of it =]
well hopefully newai...i srsly cant remmber that question so it prolly wasnt counted
 

markymark1990

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tehsky said:
whats was the BOD question? i cant remmeber seeing it in the test :|
but yeh it wasnt that hard of a test...i think i got over 70% easily...well hopefully? x)
only thing that stumped me was the cfc's equations, i forgot em =[ oh and that phosohphorus question, noOoO clue what todo =O
Hey, what was the cfc question and the question on phosphorous? Were they part of an elective or the core section? Thanks. xx
 

imraan7860

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wow i use this site like every day yet ive never commented :p, lol this forum interested me cause alot of the things i reckon i did ok in u guys found probs in and sum of the things i was :S about u guys have mentioned :| lol

hmmm ok

question 14: get this, i picked a) then d) the did the crappy arrow "correct" things back to a), meh my teacher sed it was d), i mean i can understand, but hes my physics teacher and he struggles with that too so i dunno lol

question 15: i was like :S mayb i just didnt understand the graphs it was bout AAS

fermentation/ethanol: uhhhhh it was 3 marks, i didnt mention aussie-trailia at all just its a valuable resource and we dont wanna use them crappy fossil fuels, do u really need to go into that much detail

phosphurus: i did it like a fertiliser questions sum1 sed mentioned earlier, cept i had like 2 moles for every 1 mole of the precipitate :S, but yeh i figured out moles of precipiate, then converted to moles of phosphurus and got the mass

BOD question: is eutrophication wen plants grow over the water and block oxygen, cause if so *phew* lol, yeh that part was ok for me i guess, just i didnt mention the actual way of mesuring BOD, i sed like BO(initial) - BO(after 5 days in darkness) but no practical i did

Biopolymer: im tired of these qs, not that i found it terribly hard, but thier sooooo repetitive, all i was unsure about was "how they were produced" i did PHB and all i metioned was e coli

meh nothing else been mentioned or that i memba, i reckon overall it was a good test, ive seen harder and i went into the test to be relieved lol
 

Chinmoku03

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imraan7860 said:
wow i use this site like every day yet ive never commented :p, lol this forum interested me cause alot of the things i reckon i did ok in u guys found probs in and sum of the things i was :S about u guys have mentioned :| lol

hmmm ok

question 14: get this, i picked a) then d) the did the crappy arrow "correct" things back to a), meh my teacher sed it was d), i mean i can understand, but hes my physics teacher and he struggles with that too so i dunno lol

question 15: i was like :S mayb i just didnt understand the graphs it was bout AAS

fermentation/ethanol: uhhhhh it was 3 marks, i didnt mention aussie-trailia at all just its a valuable resource and we dont wanna use them crappy fossil fuels, do u really need to go into that much detail

phosphurus: i did it like a fertiliser questions sum1 sed mentioned earlier, cept i had like 2 moles for every 1 mole of the precipitate :S, but yeh i figured out moles of precipiate, then converted to moles of phosphurus and got the mass

BOD question: is eutrophication wen plants grow over the water and block oxygen, cause if so *phew* lol, yeh that part was ok for me i guess, just i didnt mention the actual way of mesuring BOD, i sed like BO(initial) - BO(after 5 days in darkness) but no practical i did

Biopolymer: im tired of these qs, not that i found it terribly hard, but thier sooooo repetitive, all i was unsure about was "how they were produced" i did PHB and all i metioned was e coli

meh nothing else been mentioned or that i memba, i reckon overall it was a good test, ive seen harder and i went into the test to be relieved lol
For Q15, I think what you're spose to do is match the wavelength with the element in the bottom table, then find the concentration of that element by using the absorbance level of each element and the graph to find which element had 1.5ppm (I think it was 1.5... x.x; )

The biopolymer question, I just think I never understood it from the beginning. For every possible extended response question, (Like batteries, CFC's etc) my chem teacher would ask us to write an essay for it and my biopolymer essay is the only essay that I failed in the entire year x.X;
 

Martyno1

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wrxsti said:
yer exactly what i did..... got "D" in the end :)
Yep, same with me.

I'm still at a loss as to how some people got "A" for question 14? I was pretty sure it was "D", not too sure now though. :|
 

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