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Re: Chem Lab C

Posted: October 25th, 2012, 12:33 pm
by EastStroudsburg13
As long as you have some base in chemistry, it might be feasible for you to learn equilibrium. Periodicity shouldn't be too difficult, as it is mainly trends like atomic and ionic radius, electronegativity, activity, etc. Equilibrium will be decently harder, but there are probably several websites that can help you learn it. The concept of equilibrium is not very difficult, but calculations can be confusing if you haven't seen them before.

Re: Chem Lab C

Posted: October 28th, 2012, 11:24 pm
by mbdavis95
Are there any websites anyone can link that have more direct information about periodicity or equilibrium than, for example, a Wikipedia article? Also, does anyone know what types of equilibrium I should be focusing on? There are 11 different types of equilibrium from chemistry, so it would be really helpful to have a starting point. :?

Re: Chem Lab C

Posted: October 29th, 2012, 8:42 am
by Skink
I don't have a copy of the C rules, so I don't know how specifically they tell you about these topics (or if just the topics themselves), but, for equilibria, I'd guess focus on big K, acid-base equilibria, and the solubility product. If you're taking chemsitry now, to get a nice introduction, see if near the back there's an equilibrium chapter. Even in a high school level book, you could find one (they just won't cover it). There are plenty of college lecture notes and whatnot online that will go into enough detail and run through as many calculations as a textbook. If you need a textbook, getting one isn't hard.
I'd also guess it would behoove you to know how basic equations like how to convert K to Gibbs free energy and then tell whether or not the process is spontaneous at that temperature.
As far as periodicity goes, you learn the basics in a high school level class. For more, either get a college level text or an inorganic text (too much, if you ask me) to go into more detail. For online, again, look for college notes. It's all out there.

EDIT: I also forgot to mention redox equilibria. Basically, a lot of what's covered second semester in AP is a safe bet. Remember to frame your studying in terms of what lab work they can make you do, though! I'm not sure offhand what they could make you do for periodicity other than maybe build (or use) an activity series. Report back if you come up with anything on that one.

Re: Chem Lab C

Posted: December 1st, 2012, 2:51 pm
by emmamcgorray
There's some review of periodic trends (periodicity) on http://www.khanacademy.org/science/chem ... ds-bonding

Re: Chem Lab C

Posted: December 10th, 2012, 11:57 am
by fanjiatian
How will the actual lab activities be scored?
I haven't found any rubrics or anything online.

Will we have to write a lab report? What kinds of questions can be asked?

Re: Chem Lab C

Posted: December 10th, 2012, 12:02 pm
by EastStroudsburg13
There's no rubrics online because it'll be different for every event. You will almost certainly NOT have to write a lab report (that's for Experimental Design). Any lab portions you have to do will be followed by data and analysis questions, which can be both quantitative and qualitative. They will not usually grade you on the actual lab itself, but since the lab manifests itself in the questions, it's usually a good idea to perform the lab well. ;)

Of course, sometimes part of the test will be in pure written test form, where you just have to answer chemistry questions. The amount of this really varies between supervisors. It can be all test, all lab, or a mix (usually the case).

Re: Chem Lab C

Posted: January 15th, 2013, 8:21 am
by KristenEmily13
I found this table helpful in AP Chem last year and I think it will come in handy for this event as well! :D
http://upload.wikimedia.org/wikipedia/c ... trends.svg

And I found these nice quick reviews for equilibrium! (Though I think I need a more in dept review >.<)
http://web.archive.org/web/200610111809 ... 3notes.pdf
http://web.archive.org/web/200611302339 ... otes13.PDF

Re: Chem Lab C

Posted: January 25th, 2013, 11:43 am
by 135scioly
Will we be required to know how to do any lab tests for this event? Like titration? Thanks :)

Re: Chem Lab C

Posted: January 25th, 2013, 1:31 pm
by Skink
I do not have the rules in front of me, but the event is not called Chem Lab for nothing. Basic laboratory techniques are expected in this event as well as competence with sig figs, dimensional analysis, balancing reactions, stoich, et cetera as far as paper chemistry goes at a minimum.

What kind of labs? I dunno, it'll probably differ everywhere. Expect anything somehow on topic with difficulty ranges. I've seen tests that have a few minilabs and ones that have one larger labs, so it depends on the supervisor. This is just me, but I'd expect some sort of lab involving an equilibrium reaction since periodicity sounds more like straight up questions. If that is acid-base equilibria (again, see if the rules specify topics in more detail...I'm simply speculating without much to work with here), then a titration would be a very appropriate activity definitely. Weak acid and strong base titrations, diprotic (or more) acids, drawing titration curves afterwards, stuff like that...grab an AP book and read up. Of course, don't only plan for that. They could ask a wide range of stuff if there's a certain reaction where they could have you calculate big K or something that's easy to administer at a tournament. I don't know. The thing about titrations is it's easy to give the reagents to all teams along with a buret and whatnot, so it's practical, you know?

What I can say is that, from my own experience, the labs are not out of left field but do rely on you having paid attention in chemistry class.

Re: Chem Lab C

Posted: January 26th, 2013, 4:36 pm
by computergeek3
135scioly wrote:Will we be required to know how to do any lab tests for this event? Like titration? Thanks :)
You are required to know how to do labs, but the procedure is usually outlined by the supervisor...I don't think that something like a titration would be practical for a 50-minute time block (and it doesn't really relate to the topics this year). So far, I have seen two fairly easy equilibrium labs and one very easy periodicity lab. Speaking of which, you CAN anticipate having one lab for equilibrium and one for periodicity (this happened at Athens and possibly elsewhere). And I agree, @Skink, an AP Chem book is incredibly useful to learn stuff, just know that (at least in the one for my AP Chem class), equilibrium takes up several lengthy chapters.