May 10 Chemistry Paper 1 & 2

[tdubthebassist]

wait for it... just a bit and then we can discuss it!

[x___x]

hmmm, i think last year's exam was MUCH easier! i'm talking about paper 1, of course.

about paper 2, um,well, section A question 1 was really nice, it was about calcium carbonate in eggshell, meaning it was mostly calculations and mol thing.

the one about rocket fuel was good as well.

the rest is ... a disaster!!

also, i expected a question about the shapes, hybridization and theses things, but nothing of those came in paper 2.

and i'm feeling really bad about it,

but then, how did you do?

how did you solve the question asking for the energy level diagram of hydrogen? what did you draw exactly?

[IBer_101]

I drew something like this for the energy levels of hydrogen question:

For UV light, the electron goes from the n=infinity energy level to n=1 (Lyman series)

For Visible light, the electron goes from the n=infinity energy level to n=2 (Balmer series)

ionization energy is the energy associated with the transition of the electron from n=1 to n=infinity on the diagram

[Dzeb]

HL TZ2

The hydrogen question really came out of the blue. I wasn't expecting anything like this at all. But I did very similarly to the post above.

I was wondering about question 7 (acids and bases). On the whole, it was pretty easy but the part with buffer solution was tricky. Finally, I ended up with this equation for the buffer solution:

H2PO4(-) <> HPO4(2-) + H(+)

How did the rest of you do this? Was I right?

[tdubthebassist]

For UV light, the electron goes from the n=infinity energy level to n=1 (Lyman series)

For Visible light, the electron goes from the n=infinity energy level to n=2 (Balmer series)

ionization energy is the energy associated with the transition of the electron from n=1 to n=infinity on the diagram

well, it is not necessary that it comes from the infinity. In fact, the level above level n=3~4 has really small gap between levels that it actually does not matter after n=3~4 where to come from. I drew several lines from n=3, n=4, n=inf. that goes to n=1 and 2. Not sure of the lines from n=3 though. so probably I got like 3 points there if the examiner decided to penalize on n=3 to n=2 one.

[tdubthebassist]

HL TZ2

The hydrogen question really came out of the blue. I wasn't expecting anything like this at all. But I did very similarly to the post above.

I was wondering about question 7 (acids and bases). On the whole, it was pretty easy but the part with buffer solution was tricky. Finally, I ended up with this equation for the buffer solution:

H2PO4(-) <> HPO4(2-) + H(+)

How did the rest of you do this? Was I right?

??? but H2PO4 is acid...

I did not do that question though

[narathiel]

TZ 2.

So for me paper 1 was easy except like 2 questions but I reckon I got above 90%, perhaps 100%

Paper 2 was harder timewise

I reckon I got almost 100% for Section A and like 80% for section B. What did you guys write for the boiling points of cyclobutane's geo isomers?

I did not get the buffer question and when I thought of the equation time ran out.

what was it??

Paper 3 talk later....

But generally I must say P 1 and P 2 were MUCH HARDER than the last years.

Like for 2008 multiple choice paper I just took 26 minutes to answer all qs to the best of my skill, getting 90%, but this year I had to take the whole time to answer all.

I am happy cos it seems I have managed the 7 I need for studying chemistry next year.

[IBer_101]

I wrote that the cis- ismoer is more polar, and hence has dipole-dipole intermolecular bonding in addition to Van der Waal's forces. So, it has higher b.p.

[tdubthebassist]

TZ 2.

So for me paper 1 was easy except like 2 questions but I reckon I got above 90%, perhaps 100%

Paper 2 was harder timewise

I reckon I got almost 100% for Section A and like 80% for section B. What did you guys write for the boiling points of cyclobutane's geo isomers?

I did not get the buffer question and when I thought of the equation time ran out.

what was it??

Paper 3 talk later....

But generally I must say P 1 and P 2 were MUCH HARDER than the last years.

Like for 2008 multiple choice paper I just took 26 minutes to answer all qs to the best of my skill, getting 90%, but this year I had to take the whole time to answer all.

I am happy cos it seems I have managed the 7 I need for studying chemistry next year.

wow.. that is pretty awesome! paper 1 was ridiculously easy. But sometimes the answers in paper 1 are kinda unpredictable.

[x___x]

I drew something like this for the energy levels of hydrogen question:

For UV light, the electron goes from the n=infinity energy level to n=1 (Lyman series)

For Visible light, the electron goes from the n=infinity energy level to n=2 (Balmer series)

ionization energy is the energy associated with the transition of the electron from n=1 to n=infinity on the diagram

Thanks god! i did as you did.

i was worried actually, my friend said that she drew the energy level diagram, meaning the enthalpy diagram! i thought i was wrong.

[CommeDesEnfants]

Chem SL TZ1.

Paper 1: Some of the questions made me go "WTF?" A lot of them were largely doable after I thought about them more, but I was pretty paranoid about most of the paper. I know I definitely got that iron (II) sulfate equilibrium one wrong, though; I put that the crystal doesn't change. Sigh. The last question also saddened me.. Whatever happened to simple recall?

Paper 2: I thought it was okay, but the first stoichiometry question was PURE EVIL. I didn't know how to find the amount of Cu, so I just randomly divided it by the amount of S2C3 or whatever it was. My Chem teacher thought that the question was pretty nasty; who titrates brass nails, anyways? I also found the wording of that stupid "hypothesis" question misleading. Since it said "discuss," I randomly wrote that they were both wrong, since they were.

Question 3: Did you draw lone pairs on the Cl for the "Lewis" structure for chloroethene? For some reason, it looked really strange to me, since I drew it with a "bent" structure. Furthermore, for the conversion of a halogenoalkene into the halogenoalkane in Section A, were you just supposed to add H2 and a Ni catalyst on the arrow? I was pretty paranoid about that, too.

I'm also kicking myself for not writing reversible arrows for H2O + CH3COOH. I think that was only meant to be one mark, but as you can evidently tell, I really need to salvage as many marks as I can at this point, hahaha. ..

Did anybody do Question 6? The majority of my class did Question 5, but I despise redox chemistry so I opted for 6 instead. Were we supposed to write negative for the value of heat evolved in the first part? I only wrote it for the enthalpy change, which I found to be around -300 or something... I also failed at drawing another isomer for C4H10O; I went home, Googled it and realized that I could've just drawn an ester! I'm so mad, haha. I'm also paranoid that I didn't draw the SN2 correctly; do they care about how you write it? I only really know how to draw it using the 3D structure, but... Ah, well.

All in all, my question is what happened to actual chemistry?

[Cavy]

Chem HL TZ1 and I totally agree that Paper 2 SUCKED. I've been getting 7s on all projected papers that I've done for revision purposes, one short of a perfect IA score, and I did some serious revision...and I got to Paper 2 and had no idea what was going on. And who does titrate brass nails? Geez....

Anyway, Paper 1 was okay, Paper 2 Section A killed any hope I had for a 7, but Paper 2 Section B probably saved my diploma. P3 I felt awesome about but we'll discuss that more later.

I did...4 and 5 for Section B. Haber process all the way!

Totally in agreeance with the 'where did chemistry actually go'?!

[exploretheworld]

You guys got Haber Process???

TZ2 we didnt get any proper questions on Bonding/Energetics/Kinetics or Equilibria...

All we got was Periodicity, Acids and Bases (Kw ... =S), Redox and Organic CHemistry in the whole damn paper.... So you either did ok or were screwed...

[tdubthebassist]

You guys got Haber Process???

TZ2 we didnt get any proper questions on Bonding/Energetics/Kinetics or Equilibria...

All we got was Periodicity, Acids and Bases (Kw ... =S), Redox and Organic CHemistry in the whole damn paper.... So you either did ok or were screwed...

But to be honest, it was not that bad. organic was straight forward, and periodicity was alright.

[soadquake981]

I did SL TZ1 too. Paper 1 wasn't too bad. I know I missed at least a few. Paper 2 was okay, but there were some really odd questions. Yeah, question #1 was really weird. I also did #6, and I completely screwed up the last couple questions. I wrote down Sn1, and couldn't remember the whole process.

[Guest serendip.ity.]

Furthermore, for the conversion of a halogenoalkene into the halogenoalkane in Section A, were you just supposed to add H2 and a Ni catalyst on the arrow

For TZ1, SL paper 2

I didn't show a catalyst, but other than that I did the same thing as you and just added H2. However, I did show the intermediary step in the second step to form the alcohol when it underwent SN2, showing the 5-membered compound, which I'm worried they are going to be annoyed about since it said the overall equation I think....did anyone else do that?

Also, what did people write for the Alex/Hannah question? I said they were both wrong, since I2 did not affect rate, but that Hannah was closer since she identified that H2 did affect the rate. Did anyone here understand what the heck that question was asking? "Discuss"...um, ok?

[CommeDesEnfants]

I just wrote the overall equation... Darn, I'm paranoid now.

I wrote that they were both wrong because I2 didn't affect the rate. What a dumb question, though. Could've asked us on bond angles or something, but nooo.

[soadquake981]

Because the question asked us to "discuss", I explained how Alex and Hannah were both partially correct about one of the reactants. I also explained how they were incorrect about the iodine, and that one of them was additionally correct about one other thing. Sorry I can't remember specifics! The point is that I went into depth and explained how they were both right and wrong.

[Cavy]

Because the question asked us to "discuss", I explained how Alex and Hannah were both partially correct about one of the reactants. I also explained how they were incorrect about the iodine, and that one of them was additionally correct about one other thing. Sorry I can't remember specifics! The point is that I went into depth and explained how they were both right and wrong.

Woah, we were given like, two lines for that! I just sort of stared blankly...I hated, hated, HATED Section A so so so much. There was a lot of equilibrium and periodicity on our exam too though, bit odd but I was quite happy because I studied that the period before so it was fresh in my mind.

The only thing that really threw me on paper 1 was the lattice enthalpy questions...all three of them. I'm not even sure we were taught that. In fact, I couldn't find it in our book either...but no big deal haha

[soadquake981]

Woah, we were given like, two lines for that! I just sort of stared blankly...I hated, hated, HATED Section A so so so much. There was a lot of equilibrium and periodicity on our exam too though, bit odd but I was quite happy because I studied that the period before so it was fresh in my mind.

The only thing that really threw me on paper 1 was the lattice enthalpy questions...all three of them. I'm not even sure we were taught that. In fact, I couldn't find it in our book either...but no big deal haha

Wait, I did Chemistry SL, and you did HL. Did we have the same question on both exams?