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Chemistry Lab C

Posted: August 13th, 2019, 11:27 am
by pikachu4919

Re: Chemistry Lab C

Posted: November 17th, 2019, 8:46 pm
by shadowhunter
this is my partner and i's first year doing this event. what should we expect during the test?

Re: Chemistry Lab C

Posted: November 18th, 2019, 8:48 am
by splane21
shadowhunter wrote:
November 17th, 2019, 8:46 pm
this is my partner and i's first year doing this event. what should we expect during the test?
A test with chemistry questions (mostly focused on solutions and acids/bases but I've seen tests with random stuff from chemistry as well) and a lab. The test is usually formatted differently based on the difficulty of the invite (MC at easier invites versus all frq/mixed at harder invites). Additionally, there should be at least one lab. One of the labs was almost always a titration last year so make sure you can do those well. Essentially make sure you have mastered everything in the rules as well as other general Chemistry concepts as the rules really don't cover everything that is usually tested in this event at most competitions.

Re: Chemistry Lab C

Posted: November 25th, 2019, 3:56 pm
by waterlubber
Anyone have any good practice labs (especially for titrations)? New to the event this year, and although I'm generally decent at thinking on my feet I'm pretty certain that won't work for Chem.

I suppose I could use others tests, etc, but I'd like to try some non-SO labs as well, especially harder ones, just to make sure I have all my bases covered.

Re: Chemistry Lab C

Posted: January 29th, 2020, 7:01 am
by Chameleon02
For chem lab are the people supposed to provide glassware and stuff for the lab or no, cuz it says they should on the event guidelines but last year we had to bring our own

Re: Chemistry Lab C

Posted: February 3rd, 2020, 9:14 am
by ericlepanda
Chameleon02 wrote:
January 29th, 2020, 7:01 am
For chem lab are the people supposed to provide glassware and stuff for the lab or no, cuz it says they should on the event guidelines but last year we had to bring our own
The rules state that event supervisors must provide any "additional glassware" required for the tasks given. At the end of the rules, there's a chart listing the glassware and lab equipment that participants should bring. It would be best for you to bring everything listed, as the event supervisors don't need to provide those materials. Any additional materials not listed, like burets or volumetric flasks or scales, should be provided.

Re: Chemistry Lab C

Posted: February 8th, 2020, 6:29 pm
by Chameleon02
Hey guys, I had a question on content that could be tested for an invitational. If someone could please reply that would be great as I have one next week. Regarding testable content for invitationals, the rules state that buffer reactions are limited to states and nationals. Do half-equivalence reactions count as buffer reactions, and could they be tested at an invite? Ex: calculating the pH halfway to the equivalence point, at the equivalence point, etc.

Re: Chemistry Lab C

Posted: February 11th, 2020, 4:37 pm
by splane21
Chameleon02 wrote:
February 8th, 2020, 6:29 pm
Hey guys, I had a question on content that could be tested for an invitational. If someone could please reply that would be great as I have one next week. Regarding testable content for invitationals, the rules state that buffer reactions are limited to states and nationals. Do half-equivalence reactions count as buffer reactions, and could they be tested at an invite? Ex: calculating the pH halfway to the equivalence point, at the equivalence point, etc.

I would say half-equivalence points are fair game as they are relatively simple and I will argue that they fall under the titration category. I have included half-equivalence points on tests I've written for invites under that argument. Equivalence points definitely as equivalence points don't require knowledge of buffers to solve. I would say titration problems that ask you to solve for pH at other points before the equivalence point might be unlikely if following regionals rules though as it's a calculation using Henderson-Hasselback.

As a general rule of thumb for chem lab, a lot of supervisors include anything related to acids/bases or aqueous solutions unless it's explicitly banned in the rules as the rules for chem lab are not very encompassing. Thus, I would say you could be tested on anything as long as it isn't indicator theory.

Re: Chemistry Lab C

Posted: February 25th, 2020, 6:07 pm
by Galahad
Are titrations (or related-ish) labs the only ones we can expect? What else might there be?

Re: Chemistry Lab C

Posted: February 26th, 2020, 8:10 am
by splane21
Galahad wrote:
February 25th, 2020, 6:07 pm
Are titrations (or related-ish) labs the only ones we can expect? What else might there be?
According to the rules, an example is "Use freezing point depression to determine molar mass of a solute"

There are definitely a lot of labs with aqueous solutions that don't involve titrations such as qualitative analysis of cations/anions.

Keep in mind also at higher level invites and states/nationals the lab may not be a simple titration but will be multiple steps. Also higher level competitions tend to have multiple labs and only one lab may be a titration.