Official Ap Chemistry Fr Discussion

<p>I'd guess, but my school has a pretty bad AP Chem teacher, so we actually never did a practice test :-/</p>

<p>i say lets ditch this thread. I am already upset that some of the answers didnt match others. cya</p>

<p>what do you mean? everyone seems to be agreeing on answers..</p>

<p>i just wanted to make a seperate thread to get answers organized.</p>

<p>i say that the exams are over and that you cant do anything about it from here on. So lets just get this stress of AP chem out of our heads and enjoy our well deserved breaks.</p>

<p>tm2000s answers are all correct. If you don't have what he has written, then your answers are incorrect. Thankfully, I have all of his answers except formal charge (used electron PAIRS instead of single electrons around central atom!!! damnit!!!) and the shape/diagram of SF4</p>

<p>haha dude, i messed those exact samethings up!!
btw, i got ur invite, but my puters' pop up blocker won't allow me to access it :&lt;/p>

<p>primitivefuture, you're right :]. what's done is done. i'm just an obssessive freak :).</p>

<p>Hey guys a question about the wooden splint. If its pure H2 wouldn't that put out the flame? I thought Hydrogen only made a crack sound when other gases were present, but H was dominant.</p>

<p>The units for the rate law were M^-1 * s^-1 right?</p>

<p>I got C3H7O2 as the empirical formula. And for Question 8, since NaI was in a water solution, the water reacted instead of Na+ and I-, right?</p>

<p>H2 would pop (I also put that the H2 gas would ignite and flame because that's what happened when we did a lab on that way early in the year)</p>

<p>btw, my friend had the emperical formula as C6H7O2</p>

<p>that is the formula someone i know got as well...</p>

<p>i got something larger, like C11H14O4....but it was close to the other one. i think i messed up one value and so i had to double the values again</p>

<p>Actually I just looked it up
"in order to explode, hydrogen must be mixed with oxygen. In fact, a flaming splint
that is thrust into a container of pure hydrogen will be extinguished, since hydrogen does not support
combustion."<br>
<a href="http://www.chemistry.org/portal/resources/ACS/ACSContent/car_1200.PDF%5B/url%5D"&gt;http://www.chemistry.org/portal/resources/ACS/ACSContent/car_1200.PDF&lt;/a>
its on the third page, last sentence of paragraph with the "1." infront of it.</p>

<p>Yeah, that may be all well at good, but it was a glowing splint, not a flaming one. It makes a difference.</p>

<p>I'm 99% sure it pops. We do this experiment in both Chem Honors and AP Chem at the beginning of the year as sort of a "demo" thing, and it always "pops".</p>

<p>Umm.. from the same document:
"Hydrogen is very flammable, but in order
to burn, it must come in contact with oxygen, and in order to explode it must be mixed with oxygen before
being ignited. A glowing splint thrust into pure hydrogen will be extinguished"</p>

<p>Well anyway, I think the cb is looking for the answer you provided, I don't remember the setup of the experiment. I think they just said put a glowing splint into 3 bottles, what would happen. So in that case your right, as opening the bottles exposes them to air.</p>

<p>And on another site it says: "You can try collecting the gases with inverted small test tubes, and use a burning splint to test for hydrogen (the tube will pop) and a glowing splint to test for oxygen (the splint will burst into flame). "</p>

<p><a href="http://www.wcsscience.com/electrolysis/ofwater.html%5B/url%5D"&gt;http://www.wcsscience.com/electrolysis/ofwater.html&lt;/a&gt;&lt;/p>

<p>maybe it pops and then goes out? or maybe this argument has gone on way too long about way too trivial a point. yes.</p>

<p>Ya I don't know how the experiment was set up. If its actually pure hydrogen then I am right, but it probably wasn't. Well maybe they will give me 1/2 credit.</p>

<p>Maybe, but I'm pretty sure they said it was in some container and they opened it up and put in the glowing splint . . . and like people've pointed out already, opening the container would expose the hydrogen to a little O2 and thus cause the highly exothermic reaction</p>

<p>what did you guys get for the stronger acid in #1?</p>