SAT II Chemistry thread

<p>In the first few questions they asked which listed element was a good conductor of electricity in its solid form at 25C and 1 atm. The choices were bromine, oxygen, chlorine, carbon, and sulfur (not in that order). What was the correct answer? I reasoned that bromine, oxygen, and chlorine are all not solids at 25C and that I've never heard of graphite or diamonds conducting electricity so I put sulfur. Did I get it right? Also does methane dissolved in water create a slightly basic solution? thanks for the help in advance.</p>

<p>Oh, one more....one of the questions asked which of the listed reactions created the greatest increase in entropy. I eliminated all except HCl + Zn and AgNO3 + CaCl2...I think I put the first as creating the greatest increase..was I right or wrong? was it the silver nitrate reaction or another entirely? once again, thanks in advance</p>

<ol>
<li>Bromine</li>
<li>Carbon (graphite): electrical conductor (I put Sulfur too... =(</li>
<li><p>Sulfur (metallic properties)</p></li>
<li><p>Oxidation</p></li>
<li><p>Fission (40K --> 40Ar)</p></li>
<li><p>Reduction</p></li>
<li><p>Neutralization</p></li>
</ol>

<p>Zn + HCl --> ZnCl2 + H2 (g). The released gas causes this rxn to have the greatest increase in entropy.</p>

<p>More to come later.</p>

<p>i think i did so horribly on this...i put the nuclear transformation for the 40k-->40Ar one, and i put that sulfer is a better electrical conductor. </p>

<p>for the entropy, you have to remember that entropy increases as you change from a solid to a liquid, and from a liquid to a gas, so it was the one that went from a liquid to a gas.</p>

<p>The vaporizing alcohol did not constitute a chemical change. I recall quite clearly that the question asked for a chemical change. A phase change is only a physical change.</p>

<p>The 40K --> 40Ar might have been nuclear transformation now that I think about it...The equation doesn't give another product.</p>

<p>The 40 K --> 40 Ar one was electron capture obviously, and this is what I found using google.</p>

<p>CAPTURE, ELECTRON A nuclear transformation in which the nucleus captures an orbital electron.</p>

<p>fisson and electron capture weren't options...out of the choices only nuclear transformation had anything to do w/ changes in the nucleus out . damn....graphite conducts electricity? got that wrong...sulfur has metallic properties? got that wrong too....i guess i did worse than i thought..which wasn't very good at all</p>

<p>lol. i just want a 620+.......</p>

<p>i think i missed 28, and omitted about 5..what would that be around?</p>

<p>The one about Al + S, it was two moles Al right? I just realized it right after the test. I put down 1 mole.</p>

<p>yeah chem is the bomb (no pun intended) (there is no pun)</p>

<p>So what does everyone think the curve will be. if i'm lucky, i just skipped 7 and missed 6, what do you think my score'll be?</p>

<p>I think the curve should be quite generous (74-75 raw= 800?). I thought this test, especially the first 20 or so qns, was more difficult than anything I saw in Barron's.</p>

<p>but only stupid kids take the SAT's after October. Curve is going to be harsh. Hope for a 600.</p>

<p>But if only stupid kids take the test, then the curve sshould be better right? Cause the average score would be lower.</p>

<p>no.. collegeboard hates stupid kids. And also if everybody does relatively bad, and a couple of ppl do good, they can't give good grades to everyone. The curve is going to SUCK</p>

<p>I don't think you know what you're talking about because in most tests you can have a raw score of like 65 and still get a 700</p>

<p>yeah graphite was right...that's what I put. I put nuclear transformation. the answer was 2 mol for Al + S. What was question 3 again? ANy way, here is some stuff I remember: What'd u guys put for benzene as a cyclosomething structure and whether all the bonds were single or something. Also, What'd u put for adding acid to water question. Also what was that question where it said something about Pb2+ being reduced Pb compared to Ag+ reduced to Ag. Lastly, on the kinetic molecular theory question, the answer was the one on collisions.</p>

<p>benzene was the cyclic compound...but not all of benzene's bonds are single bonds....you dont add acid to water because it can boil and splatter and burn you......the Pb 2+ requires more charge because there are 2 e-/mol......</p>

<p>so for the acid one...T T CE and for the benzene one T T and for the Pb vs Ag, T T ?</p>