Official 2011 AP Chemistry Thread

Test Preparation AP Sciences
761

<p>@feedback411 - Those atoms (an atom doesn’t have any bonds by itself, the way you phrased it) would have two sigma bonds and one pi bond. The fact that there is a nonbonded pair of electrons would not matter, because there are no bonds present there. Sigma bonds and pi bonds are only concerned with covalent bonds present.</p>

<p>Remember:
Single bond = one sigma bond
Double bond = One sigma bond, one pi bond
Triple bond = one sigma bond, two pi bonds</p>

<p>Ah, I am cramming like crazy right now to make up for having an insufficient teacher. She even introduced a new chapter on Friday!</p>

762

<p>yea abrayo , 70% on both sections will get you a five, free response is always harder tho :(</p>

763

<p>@Mordred - -0.83 > -2.71
Less negative means its more likely.</p>

764

<p>There is H2O(l) available, and it has a higher reduction potential. (closer to 0) so it is reduced.</p>

765

<p>leadlol: That’s mostly for double replacement. If you form one of those it will actually form the gas.</p>

766

<p>Also H2O and Na are the only reactions being reduced</p>

767

<p>Do we need to know MO theory on ap test?</p>

768

<p>What do you guys think the 3 reactions will be this year?</p>

769

<p>@Mordred I think Na would make sense for a spontaneous reaction. However, an electric current is needed to make it spontaneous. So, the cell is carrying out a nonspontaneous reaction. I hope that made sense. :D</p>

770

<p>My teacher told me no. They typically use only the VESPR model.</p>

771

<p>Electrolytic cell is non spontaneous, but galvanic cell is</p>

<p>in other wards for a spontaneous galvanic cell :</p>

<p>ΔG = -
ΔE = +
ΔS = +
Forward reaction occurs as written</p>

772

<p>what lab safety/ lab error material is important to remember?</p>

773

<p>Do you guys think the strategy of skimming the whole MC portion and answering the easy/quick questions first would be advisable for a test like this? I know that for a practice test I took I ran out of time (might be just because I knew I wasn’t really being timed so I wasn’t prone to skipping so quickly).</p>

774

<p>Can someone explain how to do this? thanks</p>

<p>Approximately what mass of CUSO4*5H20(250g) is needed to make .25L of .1M copper(II)sulfate solution?</p>

775

<p>Can someone please tell me what I did wrong in this buffer solution problem? I also have a feeling some of my equations are wrong.</p>

<p>[imgur:</a> the simple image sharer](<a href=“http://imgur.com/5Egjb]imgur:”>Imgur: The magic of the Internet)</p>

776

<p>This is a general question:
if I’m supposed to solve for V = nRT/P in FRQ will I lose marks if I set up as PV=nRT and plug in the values, then solve directly using my calculator without rearranging the equation?</p>

<p>eeek its night already. How’re you guys doing with your revision?</p>

777

<p>highlights: You need .25*.1 moles of copper (II) sulfate in the sample. Multiply that by 250g and you should get the correct answer, 6.25 grams.</p>

778

<p>Shouldn’t lose points, but makes sense to me that you isolate the variable first before substituting.</p>

779

<p><a href=“Supporting Students from Day One to Exam Day – AP Central | College Board”>Supporting Students from Day One to Exam Day – AP Central | College Board;

<p>Question 1.e)
Why would it decrease? If the Kp is less than the original, doesn’t that mean it favours the reactants, and thus more would be produced?
Or does that only work for Ksp/Kc?</p>

780

<p>I’m kind of panicking. I’m sure I’ll do fine, but I really need a 4 or 5 to get college prereqs out of the way. I felt really good about the material, but about a month and a half ago, our awesome teacher left (family situation) and left us to this horrible, unmotivated teacher who is supposedly qualified, but her student teacher is actually doing all the teaching. HORRIFYING. </p>

<p>AAHH. I think I just need to relax.</p>