<p>Six days to go.</p>
<p>How’s everyone’s preparation going? I took a Grade 12 level Chemistry course and did a bit of studying out of the Barrons book. I think I’m fairly ready. Just need to refresh myself on how to name ethers and esters, and etc. Been doing the practise exams and an currently averaging about 4-5 wrong on the Barrons ones and 0-1 wrong on the mcGraw Hill and Kaplan ones.</p>
<p>How accurate is the Barron’s practice test for chem?</p>
<p>I don’t have the Subject bb, but it’s loads harder than the other practice exams. I think there was a question on it that asked to calculate a non-standard cell voltage at atm and 298K, which is beyond what we need to know. (at least I think so because there’s no way we’d be able to calculate log (0.2/0.04) without a calculator)</p>
<p>Is Barron’s harder than the real test?</p>
<p>I’d hope so. I’m on the cusp of an 800 on the Barrons, but solidly in 800 territory elsewhere.</p>
<p>Hey guys, how can 1 gram of carbon gives 2 liters of CO2? It is question 106 in the barron diagnostic test, and it makes me really confused about how they are going to round all the numbers like that in the actual test. When should I use the exact value, and when is 2/22.4 be rounded to 1/12 (yes indeed in the answer they said 1.07g ~ 1g, but I just need to be sure are they going to do that in the real test, because that’s a different of 0.1333l, and I think it is quite big)?</p>
<p>I’m horrible on the practice tests. The latest I got was around 630-ish.
I hope I still do well on Saturday. :(</p>
<p>@dokisame. We don’t get a calculator on the test, so I’m fairly sure the collegeboard expects us to be doing a fair amount of guesstimating. But, with that being said, that’s the only problem I’ve done where there’s a significant rounded vs. unrounded difference. Everything else I’ve done seems to be more definite.</p>
<p>i am taking it as a freshman in chemistry honors</p>
<p>i keep getting a 730 in Barron’s 
I really want a perfect score, but it seems impossible!!!</p>
<p>BTW, how many can you skip to get 800? i heard you can only skip 3, but barrons says you can skip 7</p>
<p>ALSO, I keep on messing up on the lab component!!! there’s always something random that i don’t know. i only know basic lab equipment/titrations. when barron’s asks questions about different apparatuses, i get those questions wrong. :(( (For example, page 146 Barron’s 11th Ed.)</p>
<p>Do you guys know if there will be any of those tricky lab questions on there… or is it just simple lab stuff like titrations?</p>
<p>I really hope Barron’s is harder than actual, I can consistently get over 750 on practice tests. They are pretty difficult though. Part of the difficulty is just the lack of time… there are quite a few questions I could have done if I just had an extra 5 or so minutes.</p>
<p>@Catsby, depending on the test I think you can get about 2-5 or 6 questions wrong on the test. The bb one is 2 questions wrong, raw score of 82 or above, but that’s an easy test. I think the Barron’s curve is unusually generous because it’s based on the 94th percentile and above getting 800 rather than what a SAT curve would actually look like because it is harder than the real exam.</p>
<p>oh also, are some of the Barron’s practice test answers wrong(ish)?
like one question I got wrong because it assumed conditions were STP when it never said so. another one’s answer explanation said that the most active metals are in the UPPER left of the periodic table - they’re actually at the LOWER left. I think they meant by oxidation potential rather than ionization energy - but when referring to locations on the periodic table, ionization energy is more consistent. By oxidation potential, the alkali metals go lithium > potassium > sodium which isn’t consistent by periodic table location (lithium < sodium < potassium).</p>
<p>There was also an answer that had a typo (the answer explanation had the correct answer but the answer key had a different letter)</p>
<p>Can you tell me the questions? I don’t recall wrong answers. I do recall the typo on the 3rd or 4th practice test though. </p>
<p>And also when figuring out hybridised orbitals only sigma bonds count, correct?</p>
<p>@Harrovian Yes, single bonds are no different than double or triple bonds when determining orbital hybridization.</p>
<p>I got a 670 on a practice test last night. Heck, I haven’t even touched my chemistry books since the AP Chem test. Looks like the next two nights will be dedicated to cramming.</p>
<p>BTW, what is the relationship between ionic radius and charge? Is the ionic radius trend the same as the atomic radius trend in the periodic table?</p>
<p>From what I’ve heard, you can expect about a 50 point bump going from Barron’s to the real thing.</p>
<p>@yangmaster, thanks. </p>
<p>And the ionic radius and atomic radius trends are inverse to each other. Atomic radius decreases as you go from left to right in a period but Ionic radius increases.</p>
<p>@ Harrovian:</p>
<p>Unless I’m mistaken, for ionic radius, doesn’t it actually decrease for metals as you move left to right, but increase for nonmetals?</p>
<p>Think about it, wouldn’t Ca^2+ have a smaller ionic radius that K^+? More protons.</p>
<p>If I’m mistaken, someone please correct me.</p>