AP Chemistry 2012 MC Answers

<p>80 mL after the the NaOH was added, so since there was 30 mL of NaOh, there was 50 mL of HA solution (.2 x .05= .01 mol).</p>

<p>idk i couldve just f’ed up; how many points would i get for part f based on my work? any at all?</p>

<p>First of all, that was total volume of the solution which consisted of HA and NaOH. You were supposed to find the moles of HA first. So 80-30 = 50 ml. .050mL*.2M =.01 moles.
You know that the equivalence point is well above 7. So you could have assumed that there were more moles of HA.</p>

<p>dang it…i was careless</p>

<p>Guys I think I got a raw score of approximately 65-75, enough for a 4? I really dont want a 3</p>

<p>After I see that answer for 1f, I think I got it right…</p>

<p>I’m not 100% sure though! But I remember getting 2.1E-1</p>

<p>Actually, what I remember doing was .200M x .03 L = .006 mol HA</p>

<p>.006 mol HA/.080l (total millileters) = .075L</p>

<p>Set it equal to Ka 6.3x10^-5</p>

<p>x^2/.075L = 6.3E-5</p>

<p>Multiplied .75 L by both sides</p>

<p>square root = 2.1E-3 lol.</p>

<p>@asianandproud: never seen a 4 range that low, probably a 3 if that is indeed your score</p>

<p>Here was the last released scoring summary revised for no guessing penalty. 81 was lowest 4, could be lower but it won’t be down at a 65</p>

<p><a href=“Supporting Students from Day One to Exam Day – AP Central | College Board”>Supporting Students from Day One to Exam Day – AP Central | College Board;

<p>I just recalculated and got 79 as my raw score, any chance now?</p>

<p>Wait, how are you calculating without point allocation and multipliers… Guessing? And I assume your guessing on your MC as well, right?</p>

<p>Using AP Pass very rough I know [AP</a> Pass - AP Chemistry Calculator](<a href=“http://appass.com/calculators/chemistry]AP”>AP Chemistry Test Score Calculator - AP Pass)</p>

<p>I’d say if you got about half of the points on FRQs right, you’re on pace for a 4. Hope for a score on MC in the mid-40s</p>

<p>Ah, yes, I’ve heard of it but haven’t tried it. Yeah, 79 is possible. Everybody seems to think it was hard. My students thought the FRQ was hard but on average scored less than 1 point less (out of 75) on this exam compared to the 2008 practice exam (Of course, I guessed at point allocation and they graded from memory, but a lot of them did better than they thought.</p>

<p>Here’s my analysis</p>

<p>MC: 45-55 pretty alright, scored a 63 on a practice but this was worse imo</p>

<p>1) a-d right no problem, probably not the rest
2) I hated it, only got a and b
3)got a-c and f right
4)missed the first one altogether, got 2nd and 3rd right and balanced but didn’t get the subquestion on number 3
5) Got half or a little more
6)got a-d and one subsection of e right.</p>

<p>Mr. Lynch!!!</p>

<p>^ Spam. lol</p>

<p>@uber: do I know you?</p>

<p>@hypnotoad107 what would your best guess be for the raw score cutoffs for a 3,4, and 5?</p>

<p>Yeah, and based on my analysis on the last page, what would you give me?</p>

<p><a href=“Supporting Students from Day One to Exam Day – AP Central | College Board”>Supporting Students from Day One to Exam Day – AP Central | College Board;

<p>Knock a couple of points off each and I think you’ll have close to the curve (i.e. 98 and up is a 5). Purely conjecture based off my student performance on this exam (we went over today) and the 2008 exam.</p>