AP Chemistry 2012 MC Answers

<p>Try 140s XD</p>

<p>I’ll end up at the 100-115 range haha.</p>

<p>@bleach: college board will probably be looking for some specific things, with essay questions like this, it’s always a crap shoot.</p>

<p>@ubermevin: who said I was a student ;)</p>

<p>@hypnotoad107: :o</p>

<p>hahahaa. So I guess you are a teacher(Idk) . :smiley: . But i got to admit that you are really kind.<br>
@Can’tConcentrate- Lol that is nice. I am expecting somewhere in between 115-125. Hey guess what? We were in that study room with leehannah. xD</p>

<p>did anyone not get that form but take it on the same day…?</p>

<p>@uber: student told me about this site, thought I’d check it out to see what students thought and extrapolate a curve (the more difficult, the better the curve). Saw some questions and thought I’d help out. Did screw up on that rate constant though :stuck_out_tongue: My students thought it was hard, but then they all ended up doing better than they thought when I went over the answers. End of 1 and middle of 2 just freaked them out. They made up a LOT of points in 4-6</p>

<p>how do u do part f of FRQ 1</p>

<p>@ hypnotoad. You sound exactly like my teacher. :D. My teacher did the same thing with rate constant as you did. I appreciate for working out all the problems boss. :D</p>

<p>Determine amount of HA left after reaction (.0025), and amount of A- formed (.0075). Buffer soln so use Henderson Hasselbach equation to solve for pH. then H+ from there.</p>

<p>@Adezar. Go back like one or two pages. Hypnotoad worked out all the problems.</p>

<p>@Uber: your teacher sounds awesome :)</p>

<p>Hahaha yes he does. Tomorrow, I will tell about you to my teacher. :D</p>

<p>for part F, i found the number of moles of HA and OH that were in the solution, then i did a ice table where all of the OH- disappeared so i got .016mol - .0075 mol. so the concentration of HA became .0085mol/.08 or .10625M. the concentration of A- then became .0075mol/ .08 or .09375M. then i just did the ICE table equation and did [A-][H3O+]/[HA] or [.09375][H3O+]/[.10625] = Ka which was 7.14 x 10^-5=[H3O+]</p>

<p>i thought it was similar to the Form B frq 1
<a href=“College Board - SAT, AP, College Search and Admission Tools”>College Board - SAT, AP, College Search and Admission Tools;

<p>Initial HA was .01 mol. .01-.0075= .0025 mol of HA. Not sure where you got .016.</p>

<p>@adezar: yup, pretty much exactly the same.</p>

<p>@ec1026 I had a different form also. I had form E, most people have form O (the one online)</p>

<p>i got the .016 from the .2M (80mL of solution) solution times the amount so .2 x .08= .016mol</p>

<p>i think part e is a new situation and is independent of parts a-d</p>