***Official AP Chemistry Exam Study Thread 2012-2013***

<p>You could think of it like that. Yes.</p>

<p>Huh. I genuinely never knew that! I’m feeling less and less prepared for this exam as the days go by… Even though it should be the other way around… :(</p>

<p>is there a possibility of a gas law problem, because those are the easy ones</p>

<p>On average, how many coordinate complex problems and crystal structure (face-centered, body-centered, etc.) problems are there on the exam? I’m still a bit iffy on those topics.</p>

<p>two questions:</p>

<p>Does the exam use IUPAC naming or common?</p>

<p>and is it better to symbolize the free protons as in acid reactions as hydronium or just h+?</p>

<p>I don’t think they’ll care whether you use H+ or H3O+ (neither is even truly correct). Just be consistent in what you use. IUPAC naming is primarily used.</p>

<p>Coordinate complex questions sometimes occur on number 4 of the free response as one reaction + maybe one or two other questions on it. I don’t think crystal structure is ever on the test (of the 8 practice tests I’ve done I’ve yet to see it).</p>

<p>Gas laws are pretty likely to show up on the multiple choice a few times and sometimes as a part of a free response.</p>

<p>The marking guidelines of FRQ for the past few years say you can use either H+ or H3O+. You get full points for either one.</p>

<p>I’ve done quite a few practice tests and I’ve only seen or come up once. My teacher said not to worry about it. </p>

<p>CollegeBoard accepts both H+ and H3O+. Fact.</p>

<p>OH! I understand bond order now. I was thinking about it the wrong way. Mr. Ayton’s videos helped me understand it.</p>

<p>could someone please explain question 8, parts d(i) and d(ii)? Thank you!!! <a href=“Supporting Students from Day One to Exam Day – AP Central | College Board”>Supporting Students from Day One to Exam Day – AP Central | College Board;

<p>You write the balanced half reaction for NaI -> Na+ + I-</p>

<p>You have to imagine what will happen in order to make a current on this NaI solution possible. The I- loses its electrons and must get electrons from another source. This source is the water. Therefore the oxidation half reaction is for the I- and the reduction is the H2O(l).</p>

<p>What does everyone think the FR topics are going to be this year??</p>

<p>@Diddly
When you’re predicting the products of an electrolysis reaction for an aqueous solution, the substance that will be oxidized will have a smaller standard reduction potential (E<em>) than the other oxidation half-reaction that can occur. In this case, because NaI is dissolved in water, the 3 major species in the solution are Na+, I-, and H2O. Therefore, either I- can lose an electron and be oxidized into I2 (2I- -> I2 + 2e-), or water can be oxidized to yield oxygen and hydrogen ions (2H2O -> O2 + 4H+ + 4e-). Because the E</em> for the half-reaction involving iodine is less (0.53V vs 1.23V for the water reaction), I- will be oxidized instead of water.</p>

<p>For the reduction half-reaction, the species whose half-reaction has a larger standard reduction potential will be reduced. In this case, Na+ can be reduced into Na (Na+ + e- -> Na), or water can be reduced to form hydrogen gas and hydroxide ions (2H2O + 2e- -> H2 + 2OH-). Because the half-reaction involving water has a larger value of E*, water will be reduced instead of sodium.</p>

<p>Note that there are 2 possible half-reactions for water, one for oxidation and one for reduction. It’s important not to get these mixed up.</p>

<p>If you electrolyze a molten salt solution (the salt is in liquid form, not dissolved in water), predicting the products is easier, since you only have 2 possible half-reactions to deal with. The metal cation will be reduced to the pure metal, and the anion will be oxidized.</p>

<p>Can someone please explain number 1 iv. <a href=“Supporting Students from Day One to Exam Day – AP Central | College Board”>Supporting Students from Day One to Exam Day – AP Central | College Board;
I don’t get why OH and C6H5COO the same.</p>

<p>Has anyone’s teacher made any guesses?</p>

<p>@puppylvr
My teacher is guessing that for equilibrium: most likely Kc/Kp or acid/base. Most likely not Ksp because they had that last year.</p>

<p>Last year was acid and base… </p>

<p><a href=“Supporting Students from Day One to Exam Day – AP Central | College Board”>Supporting Students from Day One to Exam Day – AP Central | College Board;

<p>2011 was ksp I believe. So I am hoping no acid and base!</p>

<p>Do you guys think there will be an electrochem question this year even though they just had one last year? I really want kinetics and electrochem. No bonding or acid/base.</p>

<p>I am actually okay with acid/base because we went hardcore that chapter. ha. But I would hate to have a laboratory situation where you would calculate molality from a freezing point depression problem. Ugh avoid avoid.</p>

<p>I want electrochem so bad as well. ;(. That chapter was so straightforward to me. Kinetics is also great; but I hate “justifying my answer”. Annoyinggg.:(</p>