Dec 3rd - SAT II Chemistry

Test Preparation SAT Subject Test Preparation
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<p><a href=“http://upload.wikimedia.org/wikipedia/commons/thumb/3/34/Phase-diag2.svg/350px-Phase-diag2.svg.png[/url]”>http://upload.wikimedia.org/wikipedia/commons/thumb/3/34/Phase-diag2.svg/350px-Phase-diag2.svg.png&lt;/a&gt; :(</p>

<p>The TF CE was so so, I remember the last one that was about isomers and the one about catalyst</p>

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<p>^^what did u say for those?</p>

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<p>What did you put for the one about the substance that would diffuse slower than nitrogen gas, and the question about the temperature when a substance evaporates? </p>

<p>Am I the only one who felt like this test was WAY harder than expected?</p>

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<p>You are not the only one… I studied with PR book and their practice tests were a lot easier.</p>

<p>@AMRF08 I remember that I put True the one about catalyst, it was the definition of a catalyst, but I forgot what were the other questions. I hope that this test has a wonderful curve!</p>

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<p>I really hope the curve is nice! I found it a lot harder than the practice tests I took, but I didn’t leave anything blank (probably should have, though)</p>

<p>got the alcohol and water separation question wrong for sure
there was a lot more lab than I was used to :(</p>

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<p>Same - I put gaseous diffusion which is DEFINITELY wrong.
For the diffusion I put the one with the largest mass. I got the evaporation wrong but I`m pretty sure the correct answer is it decreases in temperature because the molecules with higher energy left.</p>

<p>Anyone remember the one with the reaction between CaCo3 and H+</p>

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<p>It was Ca2+ and H2O.
I was going to change my answer for the diffusion one, but ran out of time :(</p>

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<p>I put gaseous diffusion too… lol</p>

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<p>Hey guys was it fractional distillation and lets start discussing answers if you guys remeber any questions in particular.</p>

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<p>CaCO3 + H{+} makes Ca{2+}, H2O, and CO2. It’s just like it was reacting with an acid.
Also for the enthalpy question, wasn’t it .5molAl2O3 reacting that you had to calculate it from? And I thought it would negative because it’s spontaneous. (I put -835 or whatever.)</p>

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<p>yea i put -835</p>

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<p>Na(s) -> Na(aq) + 1 e also was this the right equation?</p>

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<p>"The first ionization energy, IE(subscript)1, is the energy needed to remove one electron from the neutral gaseous atom to produce a unipositive gaseous ion. This process can be written</p>

<p>atom(g) + (energy = IE1) -> ion+(g) + e-</p>

<p>For sodium we write</p>

<p>Na(g) + (IE1 = 5.139 eV) -> Na+(g) + e-"</p>

<p>Source: Chemical Bonds: An Introduction to Atomic and Molecular Structure</p>

<p>For sake of the test, it would be: Na(g) -> Na+(g) + e-</p>

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<p>oh man but was it sodium that produces a yellow flame?</p>

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<p>^Yes, Na produces a yellow flame as its BLS.</p>

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<p>oh cool u guys remember any other obscure questions?</p>

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<p>no the definition of heat of formation is that you get one mol of compound from basic elements in gaseous state
2Al+3/2O2 yields Al2O3
you need to multiply by 2 so you get (-835*2)=-1670 actual is -1675.7 according to wiki
The question about the catalyst. I put false for the first part. It said that the catalyst changes the nature of the reaction. It only reduces the activation energy. The reaction proceeds as usual. I think I had 4 CEs, but I am not sure.</p>

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<p>which question is gaseous diffusion? no matter, the answer if choosing a compound would be to choose the one of the lowest molar mass. I also put fractional distilation for an answer. I got two really dumb ones wrong. I got the critical temperature one wrong and I got the one wrong about water both freezing and melting at 0. I was really dumb on those and overthought them…</p>

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<p>What was the answer to the beta particle one? I put positron, but I think I am wrong on that. How many wrong for an 800?</p>

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<p>positron is the correct answer just checked on wiki, and isnt the one where water freezes and melts at 0 C right?</p>