CSSA chemistry (1 Viewer)

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pinkcupcakes

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Re: CSSA Chemistry 2011

I fucking wrote carbon. Fucking hell if that's actually write I will cry from happiness.
hey riproot, carbon is right :) haha coz rmmbr non metals dissolved in water are acidic! :)
 
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pinkcupcakes

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Re: CSSA Chemistry 2011

did anyone get tricked by finding the average of the aas conc. In the mc?

It was sooo similar to a past hsc question, thank goodness =)

remove the outlier, then find the average, however you can only give it to 3 sig figs as it can't be more accurate than the values that were given.

noooooooooo
 
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pinkcupcakes

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Re: CSSA Chemistry 2011

haha yeah first time i did it in the hsc question i did it and left out the outlier but gave the MORE accurate answer.
Luckily, I had seen the q before.

ive seen it before too, but i forgot!!! haha damn. what bugs me is that 1 mark equates to 1%
 

Dylanamali

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Re: CSSA Chemistry 2011

haha i reckon its good that 1 mark = 1%, in comparison to other exams like eng where 1 mark = like 6% .. killer!

Did you have any other problems with the exam? What mark are you expecting?
 

hscishard

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Re: CSSA Chemistry 2011

sulfuric acid had more h+ and lower pH because it can partially dissociate another h+ ion.
From what I've gathered...
0.25 mol/L of sulfuric
0.5 mol/L of HCL
Sulfuric acid will fully disassociate itself to hydronium + HS04-. But HSO4- does not fully ionise. Hence you couldn't really multiply 0.25 by 2. hence HCL will have more hydronium ions and hence have lower ph

Is this right?
 
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Dylanamali

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Re: CSSA Chemistry 2011

From what I've gathered...
0.25 mol/L of sulfuric
0.5 mol/L of HCL
Sulfuric acid will fully disassociate itself to hydronium + HS04-. But HSO4- does not fully ionise. Hence you couldn't really multiply 0.25 by 2. hence HCL will have more hydronium ions and hence have lower ph

Is this right?
That does make sense.. but I've always learnt that to calculate the pH of sulfuric acid you just do -log(H+ x 2) because its diprotic. I ended up with equal, equal.
 
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pinkcupcakes

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Re: CSSA Chemistry 2011

haha i reckon its good that 1 mark = 1%, in comparison to other exams like eng where 1 mark = like 6% .. killer!

Did you have any other problems with the exam? What mark are you expecting?

ha true that +1
howd you find eng?
 

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hscishard

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Re: CSSA Chemistry 2011

That does make sense.. but I've always learnt that to calculate the pH of sulfuric acid you just do -log(H+ x 2) because its diprotic. I ended up with equal, equal.
Yea...I saw people doing it in class that way, but found it quite illogical. Was so tempted to go with the equal equal
 
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pinkcupcakes

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Re: CSSA Chemistry 2011

Yeah, I asked my teacher to give me booklets before hand so there were two extra on my desk. And no MC answer sheet!

Thank fuck!!!

no MC sheet? hahah dodge
 

imZerroo

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Re: CSSA Chemistry 2011

fk fk fk, i always do good in mathematical questions so i decided to be a boss and not do them the night before.
BIGGEST MISTAKE OF MY LIFE.
i have never been good at long responses, now i screwed up the mathematical crap as well.
destined to fail.
 

Dylanamali

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Re: CSSA Chemistry 2011

ha true that +1
howd you find eng?
Belonging AOS was preety sweet, probs got an 12-13/15 for essay, 14/15 for creative, but f'ed up comprehension probs 10/15 didnt have enough time..

Modules were okay probs heading B+ or higher in all of em.
 

Dylanamali

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Re: CSSA Chemistry 2011

Pinkcupcake, your sig is quite hot and is distracting me :O haha
 
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pinkcupcakes

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Re: CSSA Chemistry 2011

Belonging AOS was preety sweet, probs got an 12-13/15 for essay, 14/15 for creative, but f'ed up comprehension probs 10/15 didnt have enough time..

Modules were okay probs heading B+ or higher in all of em.
Oh, sounds good! I'm not too confident about the quality of my essays.. I memorised them that morning and they were pretty dodgy.
 

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