**********Offical AP Chemistry Prep Thread**********

Test Preparation AP Test Preparation
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<p>The test is four days from now on Tuesday May 13th.</p>

<p>I’ll start: My teacher said that acid/bases would consist of 15-20% of the test so here are some definitions</p>

<p>Arrhenius: Acid produces H+ and Bases produce OH-
Bronston-lowry: Acid is a proton donor and a base is a proton acceptor
Lewis: Acid is a electron pair acceptor, and a base is a electron pair donor</p>

<p>HA- + H20 –> H30+ + A-
Ka= [H30+][A-]/[HA-]</p>

<p>Henderson Hasselbach equation: pH=pKa + log([base]/[acid])</p>

<p>pH + pOH = 14</p>

<p>Kw = 1x10^-14</p>

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<p>Wow I spelled Official wrong… lol anyway</p>

<p>Srong acids:</p>

<p>HCl
HBr
HI
HClO4
HNO3
H2SO4</p>

<p>Polyprotic acid: more than one ionizing hydrogen like H3PO4 and H2SO4</p>

<p>Amphoteric substances: a substance that can act as both a conjugate acid and conjugate base. Ex: water, H20</p>

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<p>Oxygen count on oxyacids is one indicator of acid strength, with more oxygens meaning a stronger acid (they help weaken the H bond thus allowing it to dissociate easier). For this reason, oxyacids get stronger as their central atom gets more electronegative (generally smaller).</p>

<p>For monoprotic acids, the bigger the non hydrogen element, the stronger the acid as the bond distance gets increased.</p>

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<p>nice, i love how the name hypes up this thread and you come in and there are 3 posts :]</p>

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<p>Gases:</p>

<p>Boyle’s law: Pressure varies inversely with volume. Pressure increased, then volume decreases</p>

<p>Charles law: As volume increases, temperature increases</p>

<p>Ideal Gas Law: PV=nRT, or perv-nert, as many of you know it… maybe not :)</p>

<p>Basic Structures:</p>

<p>AX—linear
AX2—linear
AX3—Trigonal Planar
AX4—Tetrahedron
AX5—Trigonal bipyramid
AX6—Octahedron</p>

<p>Let’s keep it coming!!! Test is in only 3 days, hope you guys are studying</p>

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<p>all i m doing is taking a bunch of practice tests… i started out in low 3 range coupla days ago … now im high 3- low 4 range, hoping to get up to 5 range soon.</p>

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<p>c= frequency times wavelength</p>

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<p>▲G = ▲H - T▲S = -RTlnK = -nFE</p>

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<p>Q=IT=nF… important!!</p>

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<p>how do you make trianles…lol
thats what i want to know</p>

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<p>i was thinking the same thing.i need circles though for Nernst equation.</p>

<p>anyway, E cell= E standard cell - RT (lnk)/ n F</p>

<p>F= Faraday’s constant.</p>

<p>I hope this is correct.</p>

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<p>Acids and bases will eat me alive…especially titrations, indicators, and buffered solutions =[ ugh…</p>

<p>It’s singlehandedly keeping me from the 4-5 range but I think I can pull a three now. =/ How sucessful are two days cramming sessions in raising a three average to a five?</p>

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<p>^I want to know, too :(</p>

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<p>how much of the test is organic chem/biochem?</p>

<p>those are the only two subject matters that I’m scared about.</p>

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<p>organic chem is usually only like a question or two (sometimes none at all). Point blank, it’s not that important.</p>

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<p>π = MRTi</p>

<p>That’s a pi.</p>

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<p>

I’m pretty sure it’s Ecell = Estd.cell - RT(lnQ)/(nF) because Estd.cell = RT(lnK)/nF, and thus when Q=K, there is no electromotive force</p>

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<p>Or, E = Eº - .0592log(Q)/n</p>

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<p>er i wanna know too. Im off by a couple of points on the MC in getting a 4. FRQ, i get a 5. But i wanna know, is it possible for me to get my MC up to 5 range in the next 2 days?</p>

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<p>predictions for 2008 ap chem free response??</p>