@nhnct21 Also depends on your grader.
Glad I got the wavelength part right. Good thing I remember my spectroscopy stuff from astronomy cx
@bioisbetter can you double check that value again? I got a different answer on my calculator with your same calculations (1.8x10^-3)
@bioisbetter Thanks for taking the time to write up solutions!
I’m not sure but I got a few different answers from the ones on your form:
2d) Aren’t there 2 more electron pairs on the oxygen?
2f) My reasoning was that C2H5OH can hydrogen bond with water and is thus soluble while C2H4 is not, which means C2H4 is collected as a gas…
3e) OH NO DID WE HAVE TO DRAW THE ENTIRE CURVE? I ONLY DREW IT TO THE EQUIVALENCE POINT!!!
4b) Solids aren’t in the Ksp and the 0.10 is on the Ca2+ ions in the RICE table.
6a) I THOUGHT THEY WANTED 2 COMPARISONS UGHHHH
6b) OMIGOD I DIDN’T PUT EQUILIBRIUM
@Mochis1 since I didn’t take a formal class for AP Chem, I had to take educated guesses on things like spectroscopy because we don’t cover that in IB Chem X)
For your Ksp you left it as 4x^3=Ksp/.1 instead of 4x^2 
What do you all want to major in? Anything Chem-related?
Also for the calcium ion + water diagram I was stupid I guess and put two water molecules around the calcium. I didn’t know if they wanted us to show forces between water molecules as well so I put the other 2 around the water molecules. My diagram is correct I just don’t know if that’s what they wanted, do you think they’ll give it to me anyway? Or depends on my grader? lol
@nhnct21 AP can only give their graders instruction to a certain extent, but all your graders will be clumped up in a room together. Perhaps if a grader is unsure what to award you, they will ask their colleagues on what is best, and they will come to a somewhat unified decision on what to give you.
LOL honestly I thought I wanted to do chem-related but this course has just stressed me out so much I’m not sure if that’s what I want to do anymore hahaha. I think maybe neuroscience or chem engineering?
I think I wanna be a computer engineer for a major and then minor in chem engineering. Idk I just really like Chem. I also like explosions X)
Phew! Okay I am way too tired to math… thanks for pointing out errors, guys!
Glad to hear that a lot of people did most things correctly!
Here’s fixed again!
https://drive.google.com/file/d/0B_uKUen8BCIyZ3dLeEtOVTIyaTA/view?usp=sharing
The haber process is my favorite chemical process because it is what gives birth to bombs (not trying to sound like a German terrorist from World War I or anything)
@Dorfdude8 And makes fertilizer commercially viable 
Idk who asked this, but for something like #2, I calculated that actual moles that were actually produced with a 10^-4 instead of -3. If I did that but carried that value into the percent yield correctly, I would only lose 1 point out of both of those problems.
Uhh not sure about this but:
2f) My reasoning was that C2H5OH can hydrogen bond with water and is thus soluble while C2H4 is not, which means C2H4 is collected as a gas…
So like for the last problem, if I solved for the wrong delta H for the recycling process (I converted to grams instead of leaving in moles lol) I would lose at most 2 points? I wound up with the correct conclusion for part b I just was using a wrong number to compare.
And computer engineering also sounds interesting, both my parents do it hahaha
@Ninjadu depends on how lenient your grader will be. They might look for specifics concerning what the hydrogen bonds are attached to, but otherwise you should be fine.
That’s not wrong; in fact, considering the way the question is worded, your answer is probably better CB’s eyes, since it specifically asks about interactions with water.
The biggie is recognizing the presence of hydrogen bonds.
@nhnct21 yea I’d say up to 2 points would be what they would dock off. But I think it’s obvious to everybody who actually cares about the earth that recycling is better than trying to extract stuff (elementary school is so heavy on recycling) so if you didn’t know how to do the calculations, I think you could’ve guessed that recycling took up less energy.