Chemistry HL Paper 3

[princeton]

Can we discuss Chemistry HL Paper 3 now?

[Dzeb]

Yes, we can!

But it was pretty straight forward, there were no surprises

[tdubthebassist]

I did option A and G.

A was a bit meh as I did not study that much. I should have done better.

For the question about concentration of Cu2+, you use Beer-Lambert Law right?

you find the absorbitivity (or whatever it is called) with 1moldm-3 in log(I_o/I) = ecl

and then find c of sample using the absorbance of the sample and measuring the length of atomizer.

[narathiel]

My options were Drugs and Analytical

Drugs was easy- just what 4 points did you write for the assembling the drug library thingy

Analytical was a pain and I mighta failed it cos I only ever studied it the day before-lol.

what did you put for mobile/stationery phases for the two chromatography types and what did you put for which chromatography to use and then outlining how to use it?

for the graph I drew the peaks with same area but closer to y axis.

I said beta carotene absorbed visible light due to delocalized electrons across molecule by Pi bonds-agree??

What to put for the bonds. I said N2 was not polar so no effect and for H20 I showed asymmetrical stretch and symmetrical bending.

what did you guys put for the 4 mark copper concentration determining question?? I thought Beer Lambert is just for UV/Vis so I wrote about calibration curves.

[IB_sucks]

Wow! You guys are such liers. It doesn't seem like you didn't study to me. Don't make excuses!

[IB_sucks]

Why are you so annoyingly mfalsaf... Use an arabic dictionary to translate that.

[tdubthebassist]

My options were Drugs and Analytical

Drugs was easy- just what 4 points did you write for the assembling the drug library thingy

Analytical was a pain and I mighta failed it cos I only ever studied it the day before-lol.

what did you put for mobile/stationery phases for the two chromatography types and what did you put for which chromatography to use and then outlining how to use it?

for the graph I drew the peaks with same area but closer to y axis.

I said beta carotene absorbed visible light due to delocalized electrons across molecule by Pi bonds-agree??

What to put for the bonds. I said N2 was not polar so no effect and for H20 I showed asymmetrical stretch and symmetrical bending.

what did you guys put for the 4 mark copper concentration determining question?? I thought Beer Lambert is just for UV/Vis so I wrote about calibration curves.

graph, you got it right

beta carotene absorbs visible light, but it is because it has longer chain of conjugates.

N2 is non-polar AND bending and stretching of N2 bond does not change the dipole moment.

H2O, you got it right.

well, for that question, Absorbance = ecl equation is still valid. So you can still use the law. You only had 1 sample which was '1.00 moldm-3'. With only 1 point, you can't really make a calibration curve.

[narathiel]

"We didn't study" is relative to how much we normally study, is my view.

I said to take the copper sulfate solution and use water to make various concentrations out of it and then make the calibration curve- does that work?

what did you say for the urine?

I said HPLC and compare how long it takes for steroid to leave column with the urine and if any part of the urine leaves steroid at the same time but that is probably wrong.

[tdubthebassist]

"We didn't study" is relative to how much we normally study, is my view.

I said to take the copper sulfate solution and use water to make various concentrations out of it and then make the calibration curve- does that work?

what did you say for the urine?

I said HPLC and compare how long it takes for steroid to leave column with the urine and if any part of the urine leaves steroid at the same time but that is probably wrong.

you use GLC, but apart from that, you are all right.

and calibration curve would work.

urine, unlike many other liquid, do not decompose when vapourized. Hence GLC is the better idea.

Edited May 14, 2010 by tdubthebassist

[hermine0817]

Option C and D (Industrial Chemistry and Medicinal Chemistry). D was pretty solid, C was just plain stupid - I guess I could have studied more.

[CommeDesEnfants]

(since SL and HL Chem Paper 3s are rather similar most years, I'll just post this here.)

SL Paper 3, TZ1.

Option B = HAHA, I WAS EPIC OWNED. Bye bye 5-6 marks... Figures, the one thing I didn't really study, the actual groups involved in tertiary structure, would be on there! I also didn't get the last deficiency for diseases; I knew beriberi and goitre, but I had NEVER heard of the last one. Apparently it was vitamin B3, but major darn there.

What did people get for that iodine question? I got around 0.007 dm^3.

Option D = much better, although I wasn't sure of the more effective antacid question. I converted the grams into moles and then multiplied by 2 for Mg(OH)2 to find the amount of HCl that it would neutralize, and it was still greater than 1g of AgHCO3, so I put Mg(OH)2. Unfortunately, it didn't seem like a lot of other members of my class did...

Edited May 14, 2010 by CommeDesEnfants

[princeton]

I did option A and F in TZ1.

A was pretty good except for the function of fuel, atomizer, and monochromatic light lol didn't expect it

F was ok too except for the fact that I forgot the difference between Maillard reaction and caramelization ==

[x___x]

i had environmental chemistry option and organic chemistry..

well, environmental was really easy, especially the question about radioactive wastes.

but organic was honestly haaaaaaaaaaard! i was barely able to solve one question...

i wish i had more time to study.

[narathiel]

"We didn't study" is relative to how much we normally study, is my view.

I said to take the copper sulfate solution and use water to make various concentrations out of it and then make the calibration curve- does that work?

what did you say for the urine?

I said HPLC and compare how long it takes for steroid to leave column with the urine and if any part of the urine leaves steroid at the same time but that is probably wrong.

you use GLC, but apart from that, you are all right.

and calibration curve would work.

urine, unlike many other liquid, do not decompose when vapourized. Hence GLC is the better idea.

But urine contains hormones and proteins and many amino acids and that is what the steroid is, so it does decompose when vapourized.

[tdubthebassist]

"We didn't study" is relative to how much we normally study, is my view.

I said to take the copper sulfate solution and use water to make various concentrations out of it and then make the calibration curve- does that work?

what did you say for the urine?

I said HPLC and compare how long it takes for steroid to leave column with the urine and if any part of the urine leaves steroid at the same time but that is probably wrong.

you use GLC, but apart from that, you are all right.

and calibration curve would work.

urine, unlike many other liquid, do not decompose when vapourized. Hence GLC is the better idea.

But urine contains hormones and proteins and many amino acids and that is what the steroid is, so it does decompose when vapourized.

Yeap well, whatever you say

But I am sure that GLC is right. Revision guide clearly says that GLC is used for testing drugs for athletes.

[x___x]

anyone else had the Organic chemistry option?

[moniaa26]

Did options D (medicine and drugs) and E (environemental chemistry). Both were easy.. I think. And yeah, they were straigh forward... no surprises.

[princeton]

Ah I think I did relatively well on Paper 1 +2 and pretty decent on 3

Well, I would have to wait and see

[Tilia]

I wrote:

GLC: long chain alkanes, inert gas, such as N2

HPLC: long chain alkanes, liquid under pressure

How many points will I get for that (out of 4)?

[tdubthebassist]

I wrote:

GLC: long chain alkanes, inert gas, such as N2

HPLC: long chain alkanes, liquid under pressure

How many points will I get for that (out of 4)?

3. HPLC uses Silica Gel