The Official AP Chemistry Discussion Thread

<p>Yes! Who are you nacrogyn?</p>

<p>the kid who sits beside ethan</p>

<p>most of my problems come from the calculations believe it or not I’m the best with theories. A list of major formulas would be nice. Off the top of my head i can remember:
PV=nRT
G= delta H -(Tmultiplied by delta S)
S universe= S surroundings + S system
Molarity= mols/liters</p>

<p>Is anyone gonna cram or get a lot of sleep? I wanna sleep but then i know later on tonight ill stress about this exam.</p>

<p>Oooo ok, hey! I know you’re gonna get a 4/5 tomorrow right?!</p>

<p>abercrombie: Henderson-Hasselbalch = pH = pKa - log([A-]/[HA]).
There are other ways to find the pH from the pKa but this seems like the easiest just to memorize this.</p>

<p>activation energies??? I just need a refresher. Chemguy on youtube is great for anyone else that needs help.</p>

<p>My teacher said that stressing kills you more than a lack of understanding. I’m taking short naps between study bursts to keep up my energy and lower my stress.</p>

<p><a href=“http://www.sparknotes.com/chemistry/kinetics/mechanisms/section1.html[/url]”>http://www.sparknotes.com/chemistry/kinetics/mechanisms/section1.html&lt;/a&gt;&lt;/p&gt;

<p>Scroll down to Reaction Mechanism Coordinates for a complete explanation and chart.</p>

<p>How can you tell the difference between a Lewis acid and base?
I know Lewis acids are electron pair acceptor and Lewis bases are electron pair donor, but is there anything else?</p>

<p>One more thing, do you guys think we might have to use the real gas law equation (Van der Waals equation) on the FRQ/MC sections?</p>

<p>Don’t know what u mean by Henderson-Hasselbalch (sry) I do know ka and kb but i dont know if if that formula is related to this.</p>

<p>for anyone whos spent time doing some of the old free response questions from cb, are there any years in particular that you would recommend. I would like to do some, but seeing as time is limited I would like to do the ones that are more common and are likely to be found every year.</p>

<p>Thanks</p>

<p>lol i think you might be mixing me up with glen lol, me and fu and li are all sooo underprepared</p>

<p>If you understand electrochemistry, think of it as the Lewis base is donating the electrons much like how the anode is losing the electrons, while the Lewis acid is receiving the electrons, similar to the cathode receiving the lost electrons.</p>

<p>I would suggest doing anything from 2005 to 2008. 2005 form b is pretty fabulous.</p>

<p>hey, are the titration questions on the test like strong acid weak base or vice versa or are they just the normal ones. How big of a chance do you think there is for titrations to be on the FRQ.</p>

<p>nacro: nah, I know who you are and you’ll be fine =]</p>

<p>abercrombie: it’s not really related to any of the laws you listed. I thought you were just compiling a big formula list.</p>

<p>^^ Yes I was but can you explain it. I never heard of it</p>

<p>Lewis and brosted- lawry (sp?) acids and bases: Maybe this is a minor detail. My teacher made a big deal out of it. </p>

<p>brosted- lawry acids are proton donors (think of hydrogen. It only has a proton). bases are proton acceptors. </p>

<p>Lewis deals with electrons. Acids take in e-, bases give.</p>

<p>Ok what it does is it relates the pKa to the pH. If you have the pKa (or just Ka and then you find the pKa) of a substance, you can find the pH directly through that equation. A standard weak acid is represented by HA. so [A-] would be the conjugate base and [HA] would be the acid itself. HA <-> A- + H+. It’s kind of like equilibrium that second part of it.</p>

<p>Formuals so Far…
PV=nRT
G= delta H -(Tmultiplied by delta S)
S universe= S surroundings + S system
Molarity= mols/liters
Henderson-Hasselbalch = pH = pKa - log([A-]/[HA])</p>

<p>Hey guys, I never seem to be able to get the problems that ask Which of the following equimolar solutions will act as a buffer solution. One possible set of answer choices include
a) H2SO4, Na2SO4 b) NA2S KHS c)H2SO4 H2SO3 d)KOH KCN e)HI KI
The answer is B but I dont get it at all. Thanks</p>

<p>l refers to sublevel. in this case 1=p
6 p orbitals = 12 electrons</p>