Unit 3 Questions MEGATHREAD :)

[Water]

@luken Wednesdays get day off.

[nacho]

2008 vcaa assessment report:
they accepted:

aminoethane
ethylamine
ethanamine.

[scocliffe09]

2008 vcaa assessment report:
they accepted:

aminoethane
ethylamine
ethanamine.

But just wait until they have an easy exam and need to spread the cohort (2008 was medium I think) - VCAA will change their minds... They do it on a regular basis for methods!

[luken93]

So in summary, best to do -ylamine or -anamine if it is the primary functional group, and amino- if another group takes precedence...

and numbering, should it be X-..ylamine and X-...anamine or??

[nacho]

In summary, what do I need to know about aspirin?
I'm reading up on how it is produced, and i know how it blocks pain (as in how it attaches itself to the active site of the enzyme which oxidises the fatty acid to make that thing that sends pain messages to the brain)
is there anything else?
I didn't know it could be produced from ethanoic acid, the book only mentioned acetic anhydride

[luken93]

Acetic Anhydride is used because it is faster and gives a higher yield, hence why it's preferred.

Wouldn't hurt to know about ethanoic acid though.

[nacho]

anything else about it?

[luken93]

anything else about it?

Not that I know of, only how it reacts, what it's made of, and the functional groups present I suppose. I've never seen it questioned in depth though, but then again, feel free to surprise me VCAA.

[jane1234]

anything else about it?

I don't think you need to know in great detail how aspirin inhibits prostaglandin formation... that's bio stuff..
The main thing to be aware of is the synthesis reaction, the hydrolysis reaction and also be able to recognise the structure of aspirin and salicylic acid.
Wouldn't hurt to know the catalysts as well...

and @luken93 I think half the state gets Wednesdays or Wednesday afternoons off

[luken93]

Hahaha, yeah we get the arvo's off once a fortnight, but there were heaps of people on at like 11am haha

[Water]

I think its been confirmed ataracer, that isoelectric point is not required to be known in syllabus.

[jane1234]

^
But if you wanted to know:
The pH where a molecule (e.g. amino acid) has no net charge.

Okay concordant tires are +-0.05mL, yes?

So out of:
17.98mL
18.32mL
18.07mL
18.16mL

...there are no concordant tires right?

Lisachem thinks not, they say that 18.07mL, 18.16mL and 17.98mL are all concordant.



 

[nacho]

^
But if you wanted to know:
The pH where a molecule (e.g. amino acid) has no net charge.

Okay concordant tires are +-0.05mL, yes?

So out of:
17.98mL
18.32mL
18.07mL
18.16mL

...there are no concordant tires right?

Lisachem thinks not, they say that 18.07mL, 18.16mL and 17.98mL are all concordant.



 

I thought so too, that's what nelson chem says 0.05mL
i've also heard that it is the closest three
just to be safe, if a q ever comes up, and they're not in 0.05 range, may as well put closest three
no one is going to expect an answer of
"There are no concordant results.."

Also:
Ammonia is a weak base, which ionises in water according to the equation
NH3(aq) + H2O(l) ---> NH4+(aq) + OH-(aq).
If 20 mL of 0.10 M NH3(aq) is added to 50 mL of water, which of the following correctly
describes the expected change in pH and number of ammonia molecules, i.e. N(NH3), present
due to the dilution.
A. pH increases, N(NH3) increases
B. pH decreases, N(NH3) increases
C. pH increases, N(NH3) decreases
D. pH decreases, N(NH3) decreases

[Water]

Lisachem does their concordant results as +/- 0.10, perhaps?



On note of things, speculation. Is this year's cohurt strong?


@Nacho, is it D?

[jane1234]

Lisachem does their concordant results as +/- 0.10, perhaps?



On note of things, speculation. Is this year's cohurt strong?

Yeah that's what they said but what does VCAA define as concordant?

And no idea... I know my school cohort is heaps stronger than last year's though... even the teachers are saying it