<p>Standard conditions for gases are 0 Celsius (273 Kelvin), and 1 atm. Standard temperature for thermodynamics is 25 Celsuis (298 Kelvin, though a lot of it is change in T, so Celsius works out the same). If you think about it, most thermochemistry is conducted in solution, and it’s hard to work with an aqueous solution at water’s normal freezing point. Thus, for thermodynamics and thermochemistry, standard temperature is room temperature.</p>
<p>Is anyone else worried about not being able to get a 5? I don’t want just a very high 4, I want a freaking 5!</p>
<p>I’m not WORRIED but I am a little anxious about it. I want my 5 too :P</p>
<p>I just finished a practice test and got the absolute bare minimum for a 5 according to a grading sheet my teacher gave us (100 composite). I’m a bit worried…</p>
<p>It’s just absolutely maddening. I don’t know how else to prepare for the MC and the labs - the FRQ always seems to have the same topics and the same kind of problems, so it’s okay, but it’s the first that are going to make it or break it.</p>
<p>I haven’t started studying yet…-_- Bio is killing me. Having done USNCO is calming me a bit, but I guess I’ll freak out tomrrow.</p>
<p>I did USNCO as well, and yeah AP is a bit easier. I love concept questions. I hate chem math questions because it’s not straight math like calc, you have to do some weird things first then do the math.</p>
<p>Hmm, but do they actually use the term “standard conditions” when referring to a gas problem?</p>
<p>They should just call it STP, right?</p>
<p>I think the term “standard conditions” is reserved for 25 C, 1 atm?</p>
<p>I don’t want to see a gas problem with “standard conditions” and not know what temperature I’m working with (25 C or 0 C).</p>
<p>It’s gas at STP, and they usually include the temperature to reinforce it.</p>
<p>concept question really?? I was blindsided by those explanation questions, especially the van der waal pv = nrt with the A’s and B’s, and some delta G stuff… To me, ksp, elctrochem, acids and bases, kinetics, thermo just stick better than collegative properties and electron domain stuff.</p>
<p>In FRQ, do we have to write out like (0.02478 mol)<em>(2L/mol) to get the mols or we can simply write 0.02478</em>2?</p>
<p>you can do whatever you want as long as you have the right units for the answer.</p>
<p>does anyone know the major formulas that won’t be on the sheet, that we will need to use a lot?
(only the complicated ones)</p>
<p>This one can probably be logically figured out but still… if one needs to predict the rate constant at another temperature:</p>
<p>ln(k1/k2) = Ea/R(1/T2-1/T1)</p>
<p>Where
k1 = rate constant @ T1
k2 = rate constant @ T2
Ea = activation energy
R = gas constant (0.082)
T1 = temperature 1
T2 = temperature 2</p>
<p>What is the Cp = deltaH/deltaT formula on the sheet? When’s it used, like give me an example? It looks familiar but I can’t remember exactly when I used it.</p>
<p>^ That’s the heat capacity. Change in enthalpy over change in temperature. I’ve yet to see it used.</p>
<p>^ Ohhh makes sense. What is wrong with me… why the hell did I keep thinking it was time? It says temperature on the right. Too much sleep deprivation. But thanks. 
Overall, how are you guys feeling right now? I promised myself I wouldn’t study anything after Sunday… but of course that’s not possible.</p>
<p>this is what I use for half life --ln (final/initial) = 0.693 (T/t1/2)</p>
<p>and also E standard = 0.0257/n ln K (just my teacher)</p>
<p>gas: d = PM/RT</p>
<p>And there’s another for hydrogen spectra, but I don’t recall…</p>
<p>^ That one’s given on the sheet. It’s the very last one under atomic structure.</p>
<p>I’m so nervous for this test. More so than I was for calculus… </p>
<p>Has anyone tried taking the 1984 exam? That one seems unusually hard.</p>
<p>one more question!</p>
<p>For a potassium bromide, since both potassiums and bromides are soluble, which ones “goes away” in the reaction?</p>