*Sigh* AP chem ...

Test Preparation
61

<p>I'm getting a solid 4....if I memorize solubility rules and reactions tonight, and get the rxns, i think i'll get a 5.</p>

<p>My advice is for ppl to try and answer ALL or close to all questions. </p>

<p>cupofjoeplease21 -
1st order - if you double concentration, the rate doubles; example: Rate=k[A]; plot of [A] vs Time will make a linear graph slope=-k</p>

<p>2nd order - if conc. is doubled, then rate will quadruple (I think).<br>
Rate=k[A]^2 or Rate=[A]**; plot of 1/[A] vs Time will make a linear graph with slope=k</p>

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<p>for 1st order a graph of ln [A] v t will make a straight line</p>

<p>for 0 order a graph of [A] v time will make a straight line</p>

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<p>Can someone help me with this question? It's probably really easy but I don't know what to do. </p>

<p>In the electroplating of nickel, .200 faraday of electrical charge is passed through a solution of NiSO4. What mass of nickel is depositied? </p>

<p>(a) 2.94 g
(b) 5.87
(c) 11.7
(d) 58.7
(e) 294 g</p>

<p>Please tell me the formula to use too. Thanks.</p>

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<p>.200 faradays = .200 mols e- = .100 mols Ni2+ (2 e- for one Ni). .10 * MM of Ni (58.7g) = 5.87g .. B</p>

<p>go from current/time -> coulombs -> mol e- -> mol stuff -> gram stuff</p>

65

<p>to me, reaction prediction is absolutely the most CRITICAL source of points on the test. Get all of them (15 pts * 1.880) = 28.2 pts toward your composite score. Getting 15 instead of 5 will probably increase your grade one whole score. That's what I've really focused on, and it has paid off (I'm getting solid 5's on practice tests). Even though I rarely get more than 3 or 4 of the mandatory equilibrium points I do pretty well on rxtn prediction.</p>

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<p>Thanks Pessimist.</p>

<p>I've been wondering about the reaction predictions- does one still get 2 pts out of 3 for getting the products right and the reactants right? There's always one organic prediction (e.g. dimethyl ether burned in air), to which the products are always CO2 + H2O, but I almost never know what the formula for the organic compound is. (I suck at O-chem)</p>

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<p>just right down ?? + O2 -> CO2 + H20 and you still get 2 points.</p>

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<p>Do you know that as a fact?</p>

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<p>it is a fact.
in general, 2 pts for prods, 1 pt for rxns.
almost always all or none (sometimes they make exceptions, i.e., 1 pt on prods).</p>

<p>good luck everyone!</p>

70

<p>Rifes: The reaction section is only somewhat critical. 15 points are multiplied by 0.88, NOT 1.88, which means it equal about 8% of your composite score.</p>