General Thoughts: Chemistry (1 Viewer)

[nightweaver066]

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.

 

[LifeBoats]

dude, this is like the second time you didn't know what you were talking about :/

Do you do Industrial Chem?

 

[lance687876]

Do you do Industrial Chem?

no. did this very unpopular piece of crap chemistry of art.
oh shit. that guy was talking about some random mercury reaction. whoops! -.-

 

[LifeBoats]

no. did this very unpopular piece of crap chemistry of art.
oh shit. that guy was talking about some random mercury reaction. whoops! -.-

Yes. Please try and keep it civil with other people, even if you did misread.

 

[jeffwu95]

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]

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]

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]

What did you guys get for the aspirin question btw?

 

[someth1ng]

What did you guys get for the aspirin question btw?

Add ethanol to allow the aspirin to fully dissolve.

 

[Rawf]

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.

 

[someth1ng]

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]

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]

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.

 

[v1]

Wouldn't it be 1 sf? They said "10mL ethanol" where that is clearly 1 sf.
.

did u ever use that 10mls in ur calculations? if no its not 1 sf

 

[someth1ng]

did u ever use that 10mls in ur calculations? if no its not 1 sf

This is true.

 

[nightweaver066]

This is true.

Agreed.

 

[sarah jones]

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

 

[freeeeee]

dispersion

 

[kenkap]

i wrote hydrogen bonding...so silly!

 

[madharris]

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