<p>How accurate would you guys say that answer guide that was posted is? If it’s accurate i got 43 wrong which is freaking me out since I’ve put so many hours into this I would hate to fail so close. This test was defiantly harder than 2010’s though btw for 12 I put D but my teacher told me the extra values didn’t matter since it was just charlie’s law</p>
<p>43 should be C. Can’t be A because l=1 is p orbital and no such thing as 1p. B can’t be it because no such thing as ms=0. And D can’t be it because ml can’t =3 if l = 2.</p>
<p>I’ll have to ask my teacher and professor about 12 too.</p>
<p>I meant 43 questions wrong my teacher also said 9 was A because it forms complex ligands</p>
<p>@justin
30. i think it was confirmed that it’s actually B (that’s what it is on the google doc answer key anyways)
32. well you should take the 2.0 atm of gas and react 76% of it, leaving 0.48 atm. Then you use the stoichiometric coefficients to find that amount of sulfur dioxide and oxygen produced to be 1.52 and 0.76, respectively. The Kp is just plugging the equilibrium values into the expression.
45. it’s I and II cause there’s no change in shielding by core electrons from right to left because the core electrons are the same for the same main energy level
49. phosphorous 4 looks like this: <a href=“http://www.chemeddl.org/resources/models360/files/123286/p4-geometry.png[/url]”>http://www.chemeddl.org/resources/models360/files/123286/p4-geometry.png</a></p>
![http://www.chemeddl.org/resources/models360/files/123286/p4-geometry.png[/url]](http://www.chemeddl.org/resources/models360/files/123286/p4-geometry.png%5B/url%5D){kind=link}
<p>@jeffisaboss
it seems like the only ones that are being debated are 8 and 12
and i dont think the extra values have to do with the law itself but rather the uncertainty of extrapolation (intuitively some negative ones are more helpful to “extend” the relationship perhaps)</p>
<p>So was the ionization energy question C or D? is the consensus D?</p>
<p>8 is clearly B
[Sodium</a> peroxide - Wikipedia, the free encyclopedia](<a href=“http://en.wikipedia.org/wiki/Sodium_peroxide]Sodium”>Sodium peroxide - Wikipedia)
“it is also used as an oxygen source by reacting it with carbon dioxide to produce oxygen and sodium carbonate; it is thus particularly useful in scuba gear, submarines”
[Potassium</a> superoxide - Wikipedia, the free encyclopedia](<a href=“http://en.wikipedia.org/wiki/Potassium_superoxide]Potassium”>Potassium superoxide - Wikipedia)
“KO2 has also been utilized in canisters for rebreathers for fire fighting and mine rescue work, but had limited use in scuba rebreathers because of its dangerously explosive reaction with water”</p>
<p>thank you so much ownzandy :)</p>
<p>@jeff
im not sure but I still think number 9 is HCL cause reactions with
NaHCO3 → CO2 bubbles
AgNO3 → AgCl precipitates
Na2S → H2S odor
and CaBr doesn’t matter by then</p>
<p>also, metal complexes only have color when it’s a transition metal with unfilled d orbitals i think.</p>
<p>@jeff</p>
<p>I’m sure someone said this already, but it is potassium superoxide. While both peroxide and superoxide react with co2 to release oxygen, only the superoxide reacts with water to release oxygen.</p>
<p>sweet that would mean i got the question right. Though does everyone pretty much agrees with the answer sheet? I mean it’s not just one persons answers is it?</p>
<p>Definitely all of the calculations are correct, it is just some facts that may possible be wrong.</p>
<p>But wait Na2O2 + 2 H2O → 2 NaOH +H2O2 wouldn’t the H202 make the O2</p>
<p>Could someone create an answer sheet by consensus?</p>
<p>yeah I made that answer key based off of what everyone has been saying. lemme know if I should change anything.</p>
<p>@Jeff</p>
<p>Self contained breathing apparatus, not scuba. SCBA’s are used by firemen and contain KO2</p>
<p>Atkins, Chemical Principles, Problem 14.105 says “Cesium reacts with oxygen to produce a superoxide, CsO2, which reacts with CO2 to produce oxygen… This reaction is used as a self-contained breathing apparatus”</p>
<p>It’s been established that USNCO gets its questions directly from this textbook, so I believe the intended answer was the potassium superoxide.</p>
<p>Incidentally, does anyone know why Na2O2 isn’t used for firefighting? Maybe there’s an interesting answer hmm</p>
<p>have we reached a consensus on 12?</p>
<p>I think the video you posted reaffirms the answer as D.</p>
<p>okay i got 44 right if 12 isn’t D and 45 if it is according to the sheet posted here I should be fine with earning honors right?</p>
<p>Looks like I got 51 on the MC.</p>
<p>Some of my errors on the FR were things like doing the benzene bond stoichiometry wrong (forgetting to multiply by 2), not remembering that starch is used to tirate iodine, writing “rotates light in opposite direction” and not specifying polarized light. I think the answers to the NMR question were 7 and 4 (7 for vacuum, 4 in solution) but I wrote 4 and 7 and reversed the explanations as well.
I think that’s like minus 8 or minus 10 total. I probably missed something in reactions so minus 12 or more if I had more careless mistakes.</p>
<p>Would 51 and 88% get me camp? Seems pretty borderline. Oh well.</p>