<p>are those the compiled answers? if not can someone compile them?</p>
<p>Form b does look a bit easier, plus I love me some organic chemistry and easy bonding questions. But their lab one looks equally difficult if not worse</p>
<p>for #4 a, its H+ + OH- -> H2O because its a strong acid/strong base questions so that is the net ionic equation. Cl and Br will dissolve</p>
<p>@leadlol, i agree, form b looked much easier beside the lab question</p>
<p>Was getting form B luck or something? I got the stupid form A. Hopefully that means Ill get an “A” lol!</p>
<p>enferrari: it was solid magnesium hydroxide so it didn’t break down</p>
<p>@enferrai, Mg(OH)2 is not a strong base, it doesn’t dissociate completely.</p>
<p>I’ve got a few slight issues to some of Bioboy’s answers</p>
<p>2aiii. Volumetric flask here is significant to the thousandth place. Our next-closest measurement, in terms of accuracy, is the graduated cylinder, which is only significant to the tenths place. This added significance is unusable, so it doesn’t pay to use such a specific instrument for this dilution.</p>
<p>I believe you need to mention that the reason why the difference doesn’t matter is that the experiment calls for excess nitric acid.</p>
<p>6b. Kinetic molecular theory states that pressure and kinetic energy are directly proportional. As you increase the flask’s temperature, you increase its kinetic energy, so pressure increases too. Also, when you heat a gas, it expands, but because the beaker is rigid, pressure increases as a result.</p>
<p>Those two statements are basically the same thing and therefore shouldn’t count twice. You need to mention that an increase in average kinetic energy allows more liquid particles to possess sufficient kinetic energy to escape into a gaseous state when they collide with gaseous molecules.</p>
<p>One more slight issue.</p>
<p>4cii. Since copper cations tend to form blue solutions, the solution will likely turn blue. Also, the copper wire will decrease in mass, and a silver precipitate will form at the bottom of the solution.</p>
<p>While the copper wire’s mass decreases it is impossible to tell short of taking it out of the solution because the silver precipitate forms AROUND the wire not at the bottom.</p>
<p>For 4cii, I only put that the wire changes from brown color to silver, but only 1 point is allotted for the follow-up question. So do you guys think the wire AND solution need to be discussed to get the point or just one?</p>
<p>I would tend to think that you would need to describe both, but one may suffice. At any rate, if you put what you wrote, I wouldn’t give you credit as an AP grader in either case given that the wire doesn’t change color, the precipitate forms around it. When you pull out the wire, silver metal comes off, but the wire itself is still copper (the wire is only “dipped” so it shouldn’t react all the way).</p>
<p>I put that the copper ions formed cause the solution to appear blue and that silver precipitate appears; I would think that both observations would be noticeable in such a reaction and thus both would need to be written for full credit, but I dunno.</p>
<p>Guys for 1di, I put something like, </p>
<p>“No it will not make a good buffer because a buffer is a weak acid/base with its conjugate acid/base. By adding HCl (a very strong acid) to the solution the buffer will not be very effective.” </p>
<p>I just made that up…would I get partial credit for it?</p>
<p>For 1diii, the H+ from HCl reacts with the weak base NH3 to create NH4+. So you have .005 moles of NH4+ total (with the 0.0025 moles from the 3rd beaker). The Cl- doesn’t react with NH4+, as NH4Cl is soluble. Thus, the final molarity is .067M NH4+</p>
<p>For the second reaction question, with the Co2+ and the Cl- (I think it’s 4b?), the accepted answer seems to be: </p>
<p>Co2+ + 4Cl- –> (CoCl4)2-</p>
<p>When I saw it on the test I didn’t recognize the complex ion problem, not having seen Cl- as a ligand before. Do you think it’s okay if I wrote the product as CoCl2? I know that the coordination number is traditionally the metal’s charge doubled, but I also know that there’s some flexibility as long as the charge on the complex ion is right.</p>
<p>For #6 part c, I put that the order with respect to ethanol was zero, but then I said that the rate = k[ethanol]…
Then for c)iii, I think I actually calculated k correctly using the graph, but my units were off–I put sec^-1 instead of Mol/L-s-- because I used the rate law I made in c)ii to figure it out.</p>
<p>My question is how would the consistency points work here?
Part c)ii screwed me over because I didn’t get the right rate equation, but I got the concepts for c)i and half of c)iii.
Do you think they would give me points for the getting the correct value of k for c)iii or not because it’s not consistent with my answer in c)ii.</p>
<p>For the Electrochem problem (#3) I forgot to multiply the delta H of water given by two. And similarly for part c I used Hess’ Law, but only for one mole of water, rather than two moles. How many points would I get docked for this? Would I lose points for both parts?</p>
<p>Also, would it be acceptable to have Hydrazine hydrolyzing into a dyprotic acid? I had N2H4+2H20–>N2H6+2OH- so it becomes basic.</p>
<p>Considering that CoCl2 is not only not a coordination complex but also soluble, I doubt that you’d get credit for it.</p>
<p>If I was dumb and thought it was ammonia (which is sometimes a ligand) instead of nitrate and wrote [Co(NO3)2Cl2]2- do you think I would possibly get points? I know that it would dissociate and even if it did stay a coordination compound the NO3 would be on the outside, but do you think they’ll give me pity points? At least I know I got the follow up question.</p>
<p>Oh, shoot, will I not even get the reactant points because I included the nitrate?
This is the type of mistake I make, the dumb misreading ones. It sucks!</p>
<p>Lmao. For the Butane fuel cell problem, i saw CO2 as a product, and just started going off on a global warming/green house type discussion.</p>