<p>It did. I made one mistake on the test in the blue book, and that mistake was due solely to inattention. This was significantly harder. </p>
<p>I’m expecting an extremely generous curve. According to the blue book, 82/85 is the minimum for an 800. I expect it to be more like 79/85 for this test.</p>
<p>Really? I thought it was considerably easier than the Barron’s practice test I took. I finished that one in 45 minutes and there were some harder stoichiometry problems.</p>
<p>79/85 questions or points?</p>
<p>I did a princeton practice review test and the scale was 78 raw points for an 800…which would be 4 wrong.</p>
<p>And, does anyone remember the stoichiometry/math/balancing problems from this test? I would like to know I didn’t make stupid mistakes on those =[</p>
<p>yea i thought this was really difficult…i screwed up the descriptive chemistry stuff</p>
<p>the entahalpy, i think it was F and then something…the first one was false because it can be spontaneous no matter what the entalpy was.
what was the second part asking?</p>
<p>On copper/sulfur: I did not put that as an answer because I’m an idiot. woot.
I feel like I got so many wrong from 101 to 115, that sections annoys me.</p>
<p>1.00 was an answer (as opposed to 1, 1.0, etc)</p>
<p>There were multiple enthalpy questions, but one that hasn’t been discussed is the enthalpy of dissolution of a given compound. I don’t remember the compound specifically, but it was KCl or something like that.</p>
<p>So you know that, as temperature rises, solids are more easily dissolved in water. This is why the enthalpy of dissolution for solids is generally positive: dissolution is endothermic. </p>
<p>Of the three choices, only one was correct. I don’t remember the other two, but the correct one stated that crystallization was exothermic.</p>
<p>Today’s test was considerably easier than any of the Barron’s tests, but that’s because the Barron’s tests are much, much harder than the SAT. I finished with 15 minutes to spare, and I felt confident about my answers but now I don’t, anymore.</p>
<p>It was 3 electrons for that Cu problem. It goes from an oxidation state of 3+ to one of 6+, meaning that it loses 3 electrons.</p>
<p>Usually qualitative is harder for AP Chemistry students, while stoichiometry is much easier because there is so much focus on math at the AP level.</p>
<p>It was “Cr,” rewind.</p>
<p>Does anyone specifically remember the crystallization problem? I can’t think of it.</p>
<p>rockermcr: Yeah, I got that as an answer.</p>
<p>There was another one with 2 statements: 1) ALL endothermic reactions are nonspontaneous, 2) heat of products > heat of reactants. TT for this one?</p>
<p>^ I mentioned that KCl one a while back.</p>
<p>Yeah, I also put that crystallization was endothermic, since the reaction was simply reversed.</p>
<p>However, KCl is soluble, so I don’t see why it would crystallize in the first place.</p>
<p>1) ALL endothermic reactions are nonspontaneous, 2) heat of products > heat of reactants.</p>
<p>F,T. I’m pretty sure. And I think it was energy of products > energy of reactants</p>
<p>Endothermic reactions can be spontaneous at high temps because entropy increases. Energy of products of an endothermic reaction will always have higher energy than the reactants because energy is going in…</p>
<p>whoa wait the choices were </p>
<p>1, 1.0, 1.00, 1.000?</p>
<p>haha i thougth they were like 100, 10, 1.0, 0.1…oh crap that means i totally misread that question about volume. wow. is that really the case?</p>
<p>1) ALL endothermic reactions are nonspontaneous, 2) heat of products > heat of reactants. </p>
<p>FT; for 1. a counterexample is water melting, an endothermic reaction. This is spontaneous when T > 0 celsius. For 2., since delta H = Hfinal -Hinitial, the products have to be bigger.</p>
<p>Well, since equilibrium exists for that reaction, there is a point when KCl is temporarily solid and then dissolves in water again.</p>
<p>And, all endothermic reactions do not have to be nonspontaneous. Remember Gibb’s Free Energy equation. G=H-TS</p>
<p>All you need with a positive H is high temperature and high entropy for the equation to be spontaneous while endothermic.</p>
<p>They were 0.1, 1, 1.0, 1.00, 1.001. You need 3 digits, based on the problem, so only one that works is 1.00.</p>
<p>^ What are you talking about?</p>
<p>I don’t remember a question like that.</p>
<p>It was something like.</p>
<p>.001 HCl
.01 HCl
1 HCl
etc.</p>
<p>I put 1 HCl because it would liberate the most heat through reaction.</p>
<p>Edit: o_O I thought it simply asked what volume of solution would liberate the most heat?</p>
<p>And I think the second part of the endothermic TTCE question said because “the products have higher energy than the reactants…” which is true for an endothermic reaction.</p>
<p>They gave you three values, two of them had 5 digits, the last one had 3 digits, and the question asked had the word “recorded” in it.</p>
<p>They’re talking about a different question
Don’t remember what it involved exactly but it included dividing something by something else. The final answer was 1.00. I doubled checked that one</p>
<p>One of the answers was 1.0, I choose that. I remember that 1.001 would’ve been correct but was too precise, becuase one of the numbers in the calculation had two digits. But you all think three sig figs? Wonder what I did wrong there.</p>
<p>That was the density one. The question was something like this:</p>
<p>Mass of crucible: 20.12345 g
Mass of crucible and substance: 40.321 g
Volume of substance: 20.0 mL</p>
<p>And then they ask you for the density.</p>