USNCO: after-test

<p>While I know that last thing was a joke, piccolo, please be careful expressing (even jokingly) sentiments like that - the admissions staff at MIT are excellent people who do difficult work and do it well, and the fact that their boss lied about degrees on a resume doesn't change that.</p>

<p>I believe the molecular formula was
H2C2O4 :D
I'm fairly certain. It worked out too. It was 0.0102 L or 10.2 mL of KOH (or NaOH, it mentioned both lol) * molarity = (mass of compound/45) * 2
I can only remember the volume of KOH though, not the masses
Last year, I got 53/60 on the MC, around 80-85 on the free response, and I did not make camp- only top 50. I am guessing to make camp, one might need around a 140/160 or something at least on those two sections.</p>

<p>I know, 1of42, MIT is my first choice...I know they're great people unlike their dean, it was just a joke.</p>

<p>foolonthehill: keep in mind that last year's MC was easier (at least judging by the questions I thought so), and I thought the two sections were weighed equally...and I tend to trust Greg's numbers I mean, he did make camp so he probably knows how he thinks he did and if he says 50/85 is good then I would trust that...eh whatever. But I think it's HCO2 (even tho I put something insane because I didnt read the rest of the problem LOL!) because there was only one equivalence point.</p>

<p>Well, I ended up asking my proctor and a returning camp member about that question. It is true that the diagram was pretty crappy though. The only thing that gave it away was that H2C2O4 (oxalic acid) is a relatively guessable answer whereas I didn't even know if HCO2 is even an acid. Last year's MC was a lot easier though. This year, I got four out of the first 6 questions wrong and 4 of the last 6 wrong, so thats already 8 wrong out of 12, lol
And then for the MgO heat of formation question. I must have messed up somewhere on that question because I did not get an accurate answer for the last part, lol</p>

<p>oh, well I totally messed up the second part of the MgO question because I wasn't sure if I was using the right formula for the heat capacity of the calorimeter...I got 0.037 J/Celsius but that's most likely wrong...what was it?</p>

<p>Remember this was the one question that I would have had the fewest points on, whereas all of the others I could have gotten nearly all points as in most of question 3, all but part of 4, most of question 5, which I felt good about for once, all of the rate law question, all of the question 7 and most of question 8...had I not spent 20 minutes converting to empirical formula (still annoyed i didn't review the basics LOL!)</p>

<p>I only remember what I got for the last part... I found that dHf = -598ish kJ/mol (which is pretty close to the real value of -601 kJ/mol, so I think that I did the whole problem correctly =D)</p>

<p>Can someone post the points breakdown for the national exam (for each section, I mean)? How many points would get someone into camp?</p>

<p>I thought multiple choice was easier than last years. I think I missed 2 or 3. The free response was strange. 4-8 were pretty easy; maybe it's because I took chem last year, and we finished learning everything. 1-3 were a bit weird. I think I got the first parts of those questions correct; as the for the last part or two of those questions, I think I got owned. As for the lab, it was so much harder than last years (TITRATION OF MUSTARD!!). I think I did the first lab pretty well, but I didn't finish the second one (as in I wrote the procedure at the last minute but didn't get carry out =p). At first glance, I thought the second one was going pwn me, but it turned out to be pretty simple. I wish I had finished that one.</p>

<p>Are you sure it was overall "easier" or that you knew what they asked? I think I fall into the second category because I could see that some of the most obscure questions were asked that you could only get if you read/retained the right pieces of info.</p>

<p>If you really do as well as that (57+/85+) then good luck at camp.</p>

<p>Well, I see what you mean. There were quite a few questions that you probably can't get through reasoning...you just had to have read it or known about it.</p>

<p>Yeah... all of the organic questions owned me =D</p>

<p>LOL I was so lucky..."mild oxidation of 2-pentanol"...good thing I read that about 12 hours before LOL! (ketone)</p>

<p>Yeah, I got that wrong... I said "acid."</p>

<p>But, I think that...</p>

<p>pentanol -> oxidation -> ketone -> oxidation -> acid</p>

<p>...maybe?</p>

<p>So at least I was getting the whole "acid" thing from SOMEWHERE =P</p>

<p>no, I read it straight from Atkins (It's right in my house lol)</p>

<p>Ketones:</p>

<p>formed from mild oxidation of SECONDARY alcohols.</p>

<p>Oh, yeah, I agree with you. But I was saying that, if I remember correctly, when KETONES are oxidized they form acids. Buuut.... that's some random thing that I encountered when researching my science fair topic, so I could be wrong.</p>

<p>No, you're right (I'm pretty sure you are at least) on that part. ;)</p>

<p>Edit: I just took a practice AP Chemistry exam. All I can say is: holy ****....75 on the MC. This test is gonna be a joke(only because USNCO pwns).</p>

<p>:D</p>

<p>I know.... my brain will be so happy during the AP test =D</p>

<p>I'm expecting a perfect 5 or 5 - 10 points worse at the least. Yourself?</p>

<p>Honestly, I haven't had time to take a practice test, so I have no way to tell. I'm hoping for the same scores that you listed, though.... is there a lot of organic on the AP test?</p>

<p>hm, I think only 5% and it's all basic stuff so I doubt it should be a probelm... no mild oxidation problems ;)</p>

<p>What books do you guys use/reccomend to study for USNCO? I'm in AP Chem, and I usually can get 60-70 MCs on practice AP tests. </p>

<p>Couldn't take olympiad this year cuz of the stupid citizenship rule! What's with that anyway? Physics and bio don't have it.</p>