<p>@jamesjunkers Can you give me access to the Google Drive thing?</p>
<p>Multiple choice was okay. Naturally paranoid so I don’t dare say it was easy but I finished with 20 minutes to spare.</p>
<p>FRQ was also alright…had Form O…except for the fact I skipped a letter in the second FRQ because of time and probably got another letter wrong…and then in the third one I flipped a concept so now half of that is wrong…and I got to the last one and didn’t get to finish one letter sigh. I’m stressing too much over what’s already done and over with.</p>
<p>The MC was ridiculously easy and I had Form O. </p>
<p>@welp17 I thought the MC was incredibly hard… I finished within 45 minutes on every practice test I did, but had less than 10 answered by the time 30 minutes went by today… Once I picked up the pace and stopped being nervous, I was fine, though.</p>
<p>@welp17 I was halfway through when they called the 30 minute time mark LOL but I managed to finish the rest of it with time to spare it was weird.</p>
<p>Does anybody remember the questions about the Haber process involving the production of NH3? It said that there was no observable NH3 being produced and the 2 answers were that it had a high activation energy making it slow at 298K or that it had a really small equilib constant, so not much product is present at equilibrium… I was torn between these 2, anybody know?</p>
<p>that haber process mc question was ridiculous…I was in between the same 2 answers. i think i put activation energy, it couldn’t be small equilbrium constant b/c they stated DELtaG was negative, which means its spontaneous and K will be > 1</p>
<p>@jamesjunkers Please give me access to Google Docs. I’ll PM you my g-mail.</p>
<p>Yeah! I was torn between that question on the haber proccess as well… I picked the activation energy answer because the temperature wasn’t that great (from what I remember).</p>
<p>This is what wikipedia says about the haber process…</p>
<p>Nitrogen (N2) is very unreactive because the molecules are held together by strong triple bonds. The Haber process relies on catalysts that accelerate the scission of this triple bond.</p>
<p>Two opposing considerations are relevant to this synthesis: the position of the equilibrium and the rate of reaction. At room temperature, the equilibrium is strongly in favor of ammonia, but the reaction doesn’t proceed at a detectable rate. The obvious solution is to raise the temperature, but because the reaction is exothermic, the equilibrium constant (using atm units) becomes 1 around 150° or 200°C. (See Le Chatelier’s principle.)</p>
<p>Variation in Keq for the equilibrium
N2 (g) + 3H2 (g) ⇌ 2NH3 (g)
as a function of temperature[13]
Temperature (°C) Keq
300 4.34 x 10−3
400 1.64 x 10−4
450 4.51 x 10−5
500 1.45 x 10−5
550 5.38 x 10−6
600 2.25 x 10−6
Above this temperature, the equilibrium quickly becomes quite unfavourable at atmospheric pressure, according to the Van 't Hoff equation. Thus one might suppose that a low temperature is to be used and some other means to increase rate. However, the catalyst itself requires a temperature of at least 400 °C to be efficient.</p>
<p>Pressure is the obvious choice to favour the forward reaction because there are 4 moles of reactant for every 2 moles of product (see entropy), and the pressure used (around 200 atm) alters the equilibrium concentrations to give a profitable yield.[citation needed]</p>
<p>Economically, though, pressure is an expensive commodity. Pipes and reaction vessels need to be strengthened, valves more rigorous, and there are safety considerations of working at 200 atm. In addition, running pumps and compressors takes considerable energy. Thus the compromise used gives a single pass yield of around 15%.[citation needed]</p>
<p>Another way to increase the yield of the reaction would be to remove the product (i.e. ammonia gas) from the system. In practice, gaseous ammonia is not removed from the reactor itself, since the temperature is too high; but it is removed from the equilibrium mixture of gases leaving the reaction vessel. The hot gases are cooled enough, whilst maintaining a high pressure, for the ammonia to condense and be removed as liquid. Unreacted hydrogen and nitrogen gases are then returned to the reaction vessel to undergo further reaction</p>
<p>Those equilibrium values look pretty low too me so I guess I picked wrong? But those temperatures are a bit high as well… Not quite sure how to interpret this.</p>
<p>P.S: Give me access to the discuss docs :)?</p>
<p>For some reason, it went read only @-) </p>
<p>Try this link – <a href=“https://docs.google.com/document/d/1N4Z4VcY5Woqdk1t99JU0ilzXKL36kzXcLv-JTUC856M/edit?pli=1”>https://docs.google.com/document/d/1N4Z4VcY5Woqdk1t99JU0ilzXKL36kzXcLv-JTUC856M/edit?pli=1</a></p>
<p>I think the mc was not that bad. I probably got near a 60-70% (but I always think negatively and don’t get my hopes up anyways). After looking at a few of the posts on here though, I realize now that my FRQ was pretty bad. I focused a lot on the first 3 because they were weighted more, but I couldn’t for the life of me remember stuff about cell potentials, etc. Then I realized that time would soon be up so I freaked out and answered like one part of each of the remaining questions. So I have no idea what score I’ll get because my mc was pretty good but I bombed the FRQ. I’d say a 4ish if I’m lucky…?</p>
<p>I also had Form O.</p>
<p>Now the wait begins until July!</p>
<p>If i got a 90% on multiple choice and 50% on frq do you think i can get a 5? </p>
<p>Chatzy.com/65164467804715</p>
<p>@acttest Depending on the curve they give this year, I’d say you’re in the high 4/low 5 range, yeah.</p>
<p>I thought the multiple choice was really easy. There weren’t any that I blindly guessed on, but a few I had narrowed down to two options. The free response…that killed me. I thought I’d get a 5 from MC, but after the FRQ I’m thinking a 3.
I had form O, btw. I wasn’t even aware there was more than one form?</p>
<p>How many points are each small free response? 4?</p>
<p>That whole exam was one big OOOOPS! Haha yeah, MC was decent… maybe, There were a few I think I got right, guessed on the last 10 cause I ran out of time. FRQ was bad, I didn’t actually finish any question, I just answered the parts I could. Didn’t even attempt 6 but I wrote a chemistry joke on the lines for 6 cause I thought the grader might need a chuckle. Luckily I’m not going to be salty or beat myself up if I do bad, a 3 would be nice though.</p>
<p>Can we go over some questions that people remember?</p>