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3nv1r0nm3ntal ch3m wrote:Reading the rules yesterday, I noticed that the two topics are periodicity and equilibrium. Does anyone else think these seem like very narrow topics?

Periodicity is a little narrow, but there are still a ton of labs that can be done with it. There is so much you can do with equilibrium: gases, acids and bases, solubility, complex ions, redox, etc.

From the PA SE test, does anyone remember the details of the 32 point problem near the end? I think it was number 28. What I remember of it was 1.0 M NaOH was tirated with 18.0 mL of acetic acid. They gave us a titration curve where the equivalence point was ~8 pH at 20.0 mL of NaOH. Is there anything I'm missing from this problem? They were asking for the Ka value. Can anyone give me the answer so that I can check mine?

Not sure if anyone will find this helpful, but our lab at state consisted of two labs (one on periodicity sorta and one on equilibrium).

For the periodicity, it gave the solubility products for four different alkali earth hydroxides, then asked us to find the pH of all the solutions. For the lab portion, we got an unknown alkali earth hydroxide, and had to predict which of the four hydroxides it was.

For the equilibrium, we were given the Ka values of three weak acids. We then had to find the pH after 50.0 mL of .0500 M acid was neutralized with .0500 M NaOH. Then, we had to measure the pH of an unknown salt solution and determine which weak acid was neutralized.

What did you guys put on the Cheat Sheet?

I'm going to upload an equilibrium practice test, with answer key and explanations, to the Test Exchange soon. It contains questions from USNCO (Chemistry Olympiad) exams, so they'll likely be more difficult than the actual tests for this event, but it's good practice nevertheless.

That'll be good. There never seems to be a lot of Chem Lab resources on the wiki, so it's great you're working to improve that.

I'm going to try and get the test ready either today or tomorrow (most likely tomorrow). Answer explanations will come after it's uploaded, but it'll still be this week, so teams who are competing at States this Saturday will have access to it.
Edit: It's finally done and uploaded. Answer explanations will come later.
Edit 2: Answer explanations will have to take awhile, since they're taking me forever to type out.

SimplyNeedLogic wrote:What did you guys put on the Cheat Sheet?

AP equations and constants and a periodic table.

So, how many notes pages are you guys bringing for nationals? Reading through the forum it seems like most people used only one, but earlier in the year I got an official rules clarification that two pages were allowed (strangely, they have not put this online under Chem Lab FAQs).
Also, how many other people interpreted the rules as only allowing one page of notes per team; I just want to see how much oppostion I can expect at nationals if I bring two pages.

I think the clarification refers to the fact that you can print a page on the front and a page on the back, thus giving you two pages of information. Since the rules state you can only bring one, I doubt you will get away with two separate pieces of paper at nationals.