<p>what were the two values that it gave as delta h?</p>
<p>They were -60 and 25</p>
<p>i think i used the wrong values nooooo D:</p>
<p>No, I actually think you guys are wrong.</p>
<p>It was A(g) —> B + C DH = -60kJ
and A(l) —> A(g) DH = 25kJ</p>
<p>And you had to find the DH of A(l) —> B + C. </p>
<p>I think the enthalpy change was -85…</p>
<p>Oh damn. I allllways make the same mistake. </p>
<p>Well, that sucks. I’m hoping for a generous curve.</p>
<p>how is it -85…?</p>
<p>It would be -85 if the second reaction was A(g) —> A(l), because then you would have to flip it and thus inverse the sign.</p>
<p>Yeah, I’m pretty sure it was -35 though.</p>
<p>I felt pretty rushed at the end. Took too long at the start and the questions ended up being more difficult than I thought they would be.</p>
<p>Yeah, I think they stuck that in to trip people up
I almost made that mistake</p>
<p>rockermcr: Those reactions you posted are absolutely correct. If you add them, you’ll see that if you apply Hess’s Law correctly, the Al(g) will cancel out, leaving you with the proper reaction.</p>
<p>what other questions?</p>
<p>I’m so annoyed. I made a bunch of stupid mistakes today. I’ve caught around 6. Uuugh.</p>
<p>I made alot of stupid mistakes too. I think the questions in the first section rattled me a little…was expecting an easier test.</p>
<p>Does ANYONE have any idea of the grading curve? I just want a 760-800.</p>
<p>Grading curve is specific to each test I think…and this one seems to have been a little harder than most.</p>
<p>This test was definitely trickier than the one in the Blue Book, so I expect at least a slightly more generous curve. </p>
<p>79-80/85 will probably be an 800.</p>
<p>who knows other questions :O</p>
<p>Hmm, what did everyone get for the question with </p>
<p>2N2 -> N2O4 + heat </p>
<p>when put into cold water?</p>
<p>It’s exothermic, so the reaction should shift right.</p>
<p>1) Volume of gas increases
2) Pressure of gas increases
3) Concentration of nitrogen decreases</p>
<p>I put 3 only, it’s in a glass capsule so the volume shouldn’t increase and there’s less mols of gas on the right (which is where it shifts). Wasn’t sure though =/</p>
<p>For balancing equation problems, were there any with electron charges that had to be balanced? I realized after that I wasn’t paying attention to charges.</p>
<p>Yeah, it’s just 3.</p>
<p>Its 3. </p>
<p>1 and 2 increase if heat is increased.</p>