General Thoughts: Chemistry (2 Viewers)

lpodnano

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Ahh screwed up the calculation questions in the exam. I completely forgot that citric acid was triprotic. Normally I do pretty good at calculations. Ahfuck.
 

umz93

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It would have made a lot more sense if they used the Haber process instead since that is something that was in the syllabus and you could also talk about equilibrium/le chateliers.
Which is why i think the cut-offs are lower than last year. A lot of things were twisting the syllabus.
 

lpodnano

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Which is why i think the cut-offs are lower than last year. A lot of things were twisting the syllabus.
Just like the 'Oswald process'. Putting your knowledge of the Haber process and twisting it. Although that question wasn't bad.
 

brent012

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Which is why i think the cut-offs are lower than last year. A lot of things were twisting the syllabus.
Haha a few of my friends that did past papers almost got thrown off with the first question because they switched the usual order apparently (with hydration/dehydration). I didn't really do any past papers so i got a bit scared when i heard them saying there was a trick to the first question lmao.

Umm...having saw that question I was like wtf is with that random rod in the middle?
So just assuming it was indeed some 'random' thing and seeing as it said an 'anti-corrosion rod' I just wrote down stainless steel and how its composition/property is justified for the use.
One of my friends interpreted it this way too

Only to find out from my teacher and other guys that that 'random rod' was actually supposed to be a sacrificial anode (which it didn't mention anywhere on the question)

That being said, if the question was indeed obscure for everyone else, will BOS accept both interpretations of the Q?
Tbh, i think the reason it didn't mention sacrificial anode in the question is the criteria will probably award a mark for merely stating that it was a sacrificial anode. I also thought it was pretty self explanitory, you and your friend might not have been thinking clearly under exam pressure but why would they bother putting in a random rod which seemingly had no use (under your assumption) made out of stainless steel just so it wouldn't corrode lol. They just tried to mix things up from the usual having a slab of metal connected to underground tube or something.
 
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i wasn't sure but i wrote shit like:

"all neutralisations are essentially the same reaction, a transfer of a H+ ion (transfer of a proton), this means that all neutralisations between strong bases and acids are essentially the same so should release the same amount of heat, this happens to be 57kJ/mol"
i wrote pretty much this too LOL. i think its wrong tho
 

zhiying

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Forensics was pretty lame. Couldn't tell if it was Sucrose or Cellulose in the first question. I said Cellulose and mentioned it had an alpha glucose and beta glucose but turns out it was a sucrose with alpha glucose and beta fructose. I also mentioned it having 11 oxygen and 22 hydrogen atoms.

Hoping I can pull a mark at least for that.

Protein/Amino Qs was easy, DNA wasn't too bad, Instrumental Q was very long winded. Ran out of time to finish the testing for the presence of the sucrose, amino, potassium chloride etc but managed to list basic ways of separating.

On the whole, I'm hoping for about 17 or 18/25 in forensic.

There was no need to identify the sugar, it simply asked you to identify the structure, which is a disaccharide shown by the glucose and fructose joining by glycosidic bond. And I mentioned it was a reducing sugar due to the open chain form had a ketone group I think.
 

FaDeYagami

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first question of industrial killed me also :(... and why do we add barium sulfate into soil??
the rest are fine for me.. still hoping a band 6
 

zhiying

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barium sulfate powder is white, it's added to see the colour change more clearly
 

zhuang281

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I talked about Solvay, Frasch and NaOH as a whole (Ie, social impacts stemming from all three different cells) Think i would lose marks?

Oh and i didn't even outline the process. Only gave like 3-4 social impacts for each. G to the G
 

FCB

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In the process requiring Le chatliers principle, why was the yield always 100%. Maybe i didnt read the question correctly but i did notice that there was aqueous substances in there etc in the last step
 

BadMeetsEvil

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In the process requiring Le chatliers principle, why was the yield always 100%. Maybe i didnt read the question correctly but i did notice that there was aqueous substances in there etc in the last step
because the equation only showed one arrow indicating complete reaction. The system was not in equilibrium.
 

FCB

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do i lose 2 marks for that?
 

zhuang281

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Even for the last reaction, hope you put catalyst AND temperature increases reaction rate (But not yield ofc)
 
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aww fuck i usually get at least 20+ in options but fuck idk i was thrown off and choked (yet again). expecting about 17-18 for option fuck fuck fuck

mc was harder than usual imo, still marks to be claimed nonetheless

short answers, imo, were fairly ok. there were really str8 down the line stuff and there was also shit that could screw over majority of the state

hoping for high band 5 might *just* manage band 6 (please)

PLEASE

PL3453!!!1!
 

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