June 2010: Chemistry

<p>Does anyone know how to determine colors of solutions? And @lolchemlol: The REA tests are really difficult in my opinion in comparison to Barrons/McGraw Hill</p>

<p>@unlocked: </p>

<p>the barron’s curve is you can get 8 wrong and still get 800…(75/85)</p>

<p>which one is accurate…? I’ve been consistently getting 800’s on the barron’s practice tests but i usually get around 5-7 wrong…which according to the barron’s curve is still 800</p>

<p>um colors:</p>

<p>sodium - yellow
potassium - purple
lithium - crimson
strontium - strong red
calcium - orange-red
copper sulfate - blue
chlorine - green
barium - green</p>

<p>most of those are flame tests tho. you have to look at the precipitation reactions and see what things precipitate out and make choices based on that.</p>

<p>740 on the BB X(
ib curriculum is ridiculous, i’ve literally done only 5 units out of the 14+ being tested (doesn’t help that i’m doing really well on the 5 units i’ve done in class)</p>

<p>haha the barrons test is harder than the normal one. good on ya.</p>

<p>the barrons were the first tests that i started doing. i have done around 20 chem tests.</p>

<p>I got a 790 on the PR test I just took and a 780 on Barron’s before that. So I think I should be OK. I’ve done 3 Barrons, 3 Princeton Review, and 3 Sparknotes Tests. Any other free ones I can get now?</p>

<p>My biggest problem is Organic Chem, and remembering the solubility rules. I actually learned titrations and acid-base reactions, so that’s good. The Barron’s tests seemed hard before, but now I’m doing well. Does anyone know is the Barrons test is significantly harder or easier than the real test? Sparknotes? Princeton Review?</p>

<p>@ninmage621 - I’m basically in the same situation but based on this curve that somebody had posted here before its equal to a 780 - 790.</p>

<p>85 - 800
84 - 800
83 - 800
82 - 800
81 - 790
80 - 790
79 - 780
78 - 780
77 - 770
76 - 770
75 - 760
74 - 760
73 - 750
72 - 750
71 - 740
70 - 740
69 - 730
68 - 730
67 - 720
66 - 720
65 - 710
64 - 710
63 - 710
62 - 700
61 - 700</p>

<p>for anyone confused on solubility</p>

<p>ALWAYS SOLUBLE
all 1A are soluble
NO3-, NH4+, C2H3O2- are always soluble</p>

<p>ALMOST ALWAYS SOLUBLE
Cl- UNLESS with Ag+,Pb+2, or Hg+
SO4-2 UNLESS with PB+2, Ca, Sr, Ba (remember Casurbah)</p>

<p>NEVER SOLUBLE
remember: The “Phacs”
phosphate PO4-3
Hydroxide OH- (except with Casurbah)
arsenic
Carbonate CO3-2
Sulfur S -2</p>

<p>hope that helps peeps</p>

<p>nice!</p>

<p>anyone else feel as if Barrons is too comprehensive?</p>

<p>yes, i was about to die reading the organic chapter in barron’s, i don’t remember learning 75% of that stuff in ap chem. we only learned how to name basic compounds like alkanes, alkenes, etc. not this IUPAC 1,2,dimethlsydafliweja or whatever it is in the book, although after reading thoroughly it i guess it’s easy enough to understand, although i doubt it’s going to appear on the sat ii</p>

<p>Anyone else think the 2nd Sparknotes test wasn’t accurate (no descriptive chem. covered, etc.)??</p>

<p>Just throwing out a recommendation to you guys: make sure you spend the time necessary to memorize the basic solubility rules.</p>

<p>hey silverturtle, did you use barron’s? if so, what did you get?</p>

<p>I went through Barron’s during my sophomore year to supplement my Honors class (not to prepare for the Subejct Test itself). This year, I took one of its practice tests the night before the actual; it was my only practice test. I got about 750 on that test and 800 on the real thing.</p>

<p>750 with the barron’s curve, or with the collegeboard curve?</p>

<p>Barron’s curve.</p>

<p>How would you say a 760 with collegeboard curve on barrons test is?</p>

<p>@pickledcookie</p>

<p>I think possibly. I didn’t do so good on that one. So far…</p>

<p>Sparknotes 1: 760
Sparknotes 2: 700 (-_-)</p>

<p>how do y’all compare</p>

<p>is the barron’s curve ridiculously generous? I got 10 questions wrong (7 wrong, 3 skipped) and that totaled to a scaled score of 780-800 which seems inaccurate to me </p>

<p>do people usually score higher on barrons than the actual exam?</p>

<p>I got -6 plus 1 skip = low 800 on Barron’s</p>

<p>I’ve only taken one so far haha</p>

<p>Does anyone else hate those questions on the practice test like…</p>

<p>“Gives off a purplish vapor as it sublimes.” (Iodine, I2)
“Which of the following solids has a brilliant blue color?” (CuSO4)
“Will be colored blue.” (Cu(NO3)2)
etc…</p>

<p>I dont get how we’re supposed to know these -_-</p>