June 2010: Chemistry

<p>it was a cis and trans isomer. the answer is I + II</p>

<p>I mean, what prep books did u guys use and how well/not well did they cover the material?</p>

<p>@dwarf
Like “Fe” without the oxidation state.</p>

<p>i didnt use any prep books. i just did a practice test from sparknotes the night before.</p>

<p>If you miss two (two wrong), you get -2.5 off raw score. Do they round to 83 or 82?</p>

<p>What if you get 3 wrong?</p>

<p>I used Princeton review, which I only bought last saturday and studied for 6 days. My chemistry class did not cover the equilibrium stuff/enthalpy/entropy/Dissociation constants/organic chemistry/electrochemistry (we only did a few questions on assigning charges on elements and my workbook) </p>

<p>First practice test I did on sparksnotes I got 510. (timed)
A second practice test in PR I got 680 (untimed)
3rd test, in PR and got 710 (untimed).</p>

<p>I did not manage to do a timed test before saturday since I was struggling to memorize all the material that our class did not cover. But I’d say that the book really does the job of preparing you for the TEST itself, without any superfluous information.</p>

<p>Anyone have an inkling as to what the curve might be?</p>

<p>Well, anyone know the curve for the May test?</p>

<p>Barron’s covered all the information you could possibly need. Maybe too much information. It also has really hard practice tests. I basically only studied last night, I skimmed through all the subjects I knew and studied things that we didn’t cover in class, and I felt like I knew everything that I saw on the test.</p>

<p>Does anybody remember the Part B question about the geometry for CCl4? I said TT. What did you guys get?
And I think Barron’s review was over prep by a bit, and Princeton Review was right on the money.</p>

<p>Lol I used barron’s too. I got 800s on their 1st 2 practice tests (just barely haha)</p>

<p>AND I GOT RAPED.</p>

<p>Ok I need to know this, because it might be the difference between a 790 and 800
–ARE YOU GUYS ABSOLUTELY COMPLETELY SURE ABOUT THE I, II, III QUESTION ABOUT SALTWATER –> Did one of the choices (I’m pretty sure it was I) say that the freezing point would be lower? I COULD OF SWORN IT SAID “FREEZING POINT WILL STAY THE SAME”</p>

<p>Like I remember the question like this:</p>

<p>I. Freezing point stays same
II. It will be denser/heavier
III. Boiling point increase</p>

<p>So I put II and III (I’m actually not that sure about the numbers, but you get the point)</p>

<p>do you guys think there’s a chance that -5 or -6 will be a 780-790 this time?</p>

<p>edit: wth is this salt water question? I don’t remember it at all …</p>

<p>@Education I don’t remember what Statement II was, but I remember getting False for Statement I. </p>

<p>If my memory serves me correctly, Statement I was that CCl4 was a square planar geometry. However, square planar is characterized by 4 bonds and 2 pairs of unshared electrons. CCl4 is a tetrahedral, as it has no pairs of unshared electrons.</p>

<p>@Iamcool. I don’t remember any salt water question either, so there must be two versions.</p>

<p>alright - clearing stuff up
of course there’s more than one version of the test.
that’s the reason they make you fill out that seemingly superfluous information RIGHT before you take the test and the proctor says: “if you fill in this section incorrectly, your answers may not score correctly.”
in fact, it’s very possible that it could have said “total electrons” on one and “valence electrons” on the other…etc. </p>

<p>most questions i think though are the same.</p>

<p>^^yeah same, square planar is a d2sp3 hybridization so no way CCl4 is square planar</p>

<p>i think the other statement was whether or not the bonds were equal length? which they are so one answer was true and the other was false</p>

<p>Ahh but it said the molecular geometry, and, since a question like this was on Princeton Review before, I’ll tell what the PR book said. Basically, it stated that molecular structure, as opposed to geometric structure, is what the molecule looks like without its unbonded electrons. And in CCl4’s case, it would look identical to a square planer shape. </p>

<p>Also, isn’t square planer the same thing? I looked up an image on google and it showed it being identical to tetrahedral.</p>

<p>EDIT- Nevermind, square pyramidal is different, I wasnt thinking in 3D. The molecular vs geometric structure is true though, unless I understood the question wrong…</p>

<p>Hope I did well. I never bothered to learn about any relevant scientists/chemists. So that’s at least one question down the tube. BTW, do you lose points if you get one of the T/F/CE questions wrong?</p>

<p>I do not remember answering a question about salt lowering the boiling point. does anyone remember where it was?</p>

<p>in square planar, the spare pair of electrons on the top and bottom of the central electron repel the bonds away from the electron pairs, so the angles are different. so tetrahedral and square planar have different bond angles i think</p>

<p>Nope. CCl4 is Tetrahedral Both molecular and Electron geo…Yea that salt water statement was really I.Boiling point stays the same
II.It is denser
III. Freezing point decreases
It is 2 and 3</p>