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General Thoughts (1 Viewer)

kalstar

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no the HSC chem papers are not scanned, as they did not have the little right angles at each corner of each page. In business studies however it did, and i know for a fact that they only started scanning them last year. for now (2013) chemistry is not scanned, or it would have specific margins for which you would have to write it. dw, i wrote a fuckload too.
Why the big font?
 

bangladesh

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Good job with the 19/20 though lol
Hahahah thank you! Hopefully it'll turn into a 20 :p I will actually burn if the answer is D, because during the test i was like.. Everyone is gonna put D but maybe they're trying to trick us so i put A considering A could still be produced from plant material. Still happy with 19/20 hurhur :)

Hope you've done well too :)
 

Menomaths

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Hahahah thank you! Hopefully it'll turn into a 20 :p I will actually burn if the answer is D, because during the test i was like.. Everyone is gonna put D but maybe they're trying to trick us so i put A considering A could still be produced from plant material. Still happy with 19/20 hurhur :)

Hope you've done well too :)
Lol, it's either you get 20/20 and I get 19/20 or you get 19/20 and I get 20/20.

You know which one I'm hoping for ;)
 

bangladesh

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Lol, it's either you get 20/20 and I get 19/20 or you get 19/20 and I get 20/20.

You know which one I'm hoping for ;)
HAHAHHA... It's okay. I am pretty happy with my core as well. Don't think 1 mark would matter that much :)))))
 

superSAIyan2

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What did everyone say to increase validity for the titration question.
I said just squeeze the ball of the pipette till no more solution can come out since the graduated mark on the pipette accounts for the little bit of solution that remains near the tip of the pipette. So if the guy blew on the pipette, he has transferred extra volume of solution.

Some of my friends said add distilled water to the pipette to get the extra bit of solution out. I dont think is right though? Anyone care to confirm
 

leesh95

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I said just squeeze the ball of the pipette till no more solution can come out since the graduated mark on the pipette accounts for the little bit of solution that remains near the tip of the pipette. So if the guy blew on the pipette, he has transferred extra volume of solution.

Some of my friends said add distilled water to the pipette to get the extra bit of solution out. I dont think is right though? Anyone care to confirm
I said what you said and I think its right. The pipette is made to account for the little droplets that stay behind at the end.
 

superSAIyan2

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What exactly was the question?
It listed the steps in which some boy conducted a titration. One of the steps was that he used a pipette to transfer a standard base to the conical flask. He blew on the end of the pipette to ensure that all of the liquid was transferred.

Outline a problem in this step and propose a change to improve the validity of this? 2M
 

hayabusaboston

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It listed the steps in which some boy conducted a titration. One of the steps was that he used a pipette to transfer a standard base to the conical flask. He blew on the end of the pipette to ensure that all of the liquid was transferred.

Outline a problem in this step and propose a change to improve the validity of this? 2M
I thought it was "Outline how the HCl concentration is affected and propose a solution to improve validity"?
 

leesh95

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i did some research and found that air-displacement pipettes (the ones we use in labs) are meant to have some liquid contained in the tip
http://en.wikipedia.org/wiki/Air_displacement_pipette
http://www.pipette.com/public/staticpages/guidetopipetting.aspx
so hopefully we're right
I am 99.9% sure on this. I've done the titration prac and pretty sure that the last few droplets of water remain behind in the pipette.

What your friend said though sounds really dodgy. If you add water to the solution in the pipette that would change the concentration of the base giving a wrong titration result. I doubt that correct
 

superSAIyan2

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^ but it wouldnt matter if the concentration of the solution in the conical flask changes since the number of moles stays constant.

Nevertheless im quite sure that this is wrong.
 

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