General Thoughts: Chemistry (1 Viewer)

nightweaver066

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Yeah, 299.2mg (4sf)
Wouldn't it be 1 sf? They said "10mL ethanol" where that is clearly 1 sf.

What about the pH question ?
Did anyone get 2.397 something ?
I round it to 2.40 ==*
Feel like i got wrong answer
I got that too. I got 1.397 first (not sure if it exactly was this) and found i didn't recalculate the concentration, and changed it to 2.397.
 

jeffwu95

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For the eutrophication question, I don't think DO/BOD is enough personally- I mentioned this quickly but I think you have to go into nitrate/phosphate tests (like colorimetry, Kjeldahl method etc.). Just my two cents though
i wrote do, bod and kjeldalh (Y)
 

habitres

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no. did this very unpopular piece of crap chemistry of art.
oh shit. that guy was talking about some random mercury reaction. whoops! -.-
Chemistry of Art is the shit man. Half of it is astrophysics.
 

Rawf

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Oh my gosh, the nitrates and phosphates question.. my heart sunk when I saw it. I was completely clueless and I wrote about AAS LOL (i know that sounds super wrong as it only works for cations).
Do you think I will get at least 1 mark for writing that it has to be monitored as nitrates and phosphates provide a source of nutrients in the water which brings about favourable conditions for algal blooms to grow?
 

Rawf

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What did you guys get for the aspirin question btw?
 

Rawf

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Add ethanol to allow the aspirin to fully dissolve.
I wrote to aid the blending of the aspirin and water or something like that o_o I read earlier in this thread that we had to discard the first/rough titre? Is this true? I didn't... I though it wasn't that different from the other two results so i used all 3 and got 0.1mol/L NaOH :( My final ans was like 300mg or something like that.
 
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someth1ng

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I wrote to aid the blending of the aspirin and water or something like that o_o I read earlier in this thread that we had to discard the first/rough titre? Is this true? I didn't... I though it was that different from the other two results so i used all 3 and got 0.1mol/L NaOH :( My final ans was like 300mg or something like that.
You don't need to remove the first one because in the exam, they only gave 3 - normally they give 4 and ask to titrate using 3.
 

Rawf

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You don't need to remove the first one because in the exam, they only gave 3 - normally they give 4 and ask to titrate using 3.
Ahh sweet :) yeah using 2 titres seems a bit too little. I also made a typo in my post lolol i was meant to say "i didn't think the rough titre was that different from the other two titres".
 

someth1ng

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Ahh sweet :) yeah using 2 titres seems a bit too little. I also made a typo in my post lolol i was meant to say "i didn't think the rough titre was that different from the other two titres".
Yeah, normally, 2=shit reliability.
 

sarah jones

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what did you guys say for the force responsible between the alkanols and the increasing boiling points? :)
 

madharris

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i wrote hydrogen bonding...so silly!
yeah it was dispersion because they were the same series.
Hydrogen bonding would be for example comparing alkanols and alkanes
 

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