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Re: Forensics C

Posted: January 31st, 2014, 1:59 pm
by haverstall
Well, unless NY has different rules for Forensics (which might be possible), I've never done a CO2 test before. I would suggest revamping your flowchart-it sounds like you're basically using a previous copy, which isn't a problem. But sometimes it is best to create your own flowchart just so you have more familiarity with it.

Re: Forensics C

Posted: February 3rd, 2014, 4:31 pm
by fatcamels
The rule sheet says "each student may bring one 8.5" x 11" two-sided page of notes containing information in any form from any source" Does this mean we get up to 2 notesheets?

Re: Forensics C

Posted: February 3rd, 2014, 4:46 pm
by iwonder
Yup, one per person, but we really just share both of them during the contest. You won't know what to do with the extra space ;)

Re: Forensics C

Posted: February 13th, 2014, 1:42 pm
by BoldlyGoingNowhere
csattom wrote:On the flow chart to test for powders that we have it list to perform a co2 test. Which we have been unable to figure out how to perform.
For a powder test, you don't technically have to use anything. Perhaps it's useful, but only use what you need. I've been in this event for three years and never even heard of a CO2 test, so I wouldn't bother.

Re: Forensics C

Posted: February 25th, 2014, 2:13 pm
by BoldlyGoingNowhere
Can anyone explain how to study mass spectra? I never have understood that part of this event.

Re: Forensics C

Posted: March 9th, 2014, 10:06 pm
by darkwinters
BoldlyGoingNowhere wrote:Can anyone explain how to study mass spectra? I never have understood that part of this event.
I haven't been able to find much on it.

From what I have seen, it really is just a matter of comparing peaks (and knowing that the area underneath spikes gives you the relative concentrations of those elements).

Does anyone know how to test for a difference between sodium hydrogen carbonate and sodium carbonate?

Re: Forensics C

Posted: March 11th, 2014, 9:47 am
by vxpvm
http://www.chem.arizona.edu/massspec/ this is a nice place to start if you want to learn how to read them, but I would also suggest just memorizing the appearance of the mass spectra of common compounds like acetone or isopropyl alcohol. Use pH for sodium bicarbonate vs sodium carbonate.

Re: Forensics C

Posted: March 11th, 2014, 8:32 pm
by spackenkillkid
darkwinters wrote:
BoldlyGoingNowhere wrote:Can anyone explain how to study mass spectra? I never have understood that part of this event.
I haven't been able to find much on it.

From what I have seen, it really is just a matter of comparing peaks (and knowing that the area underneath spikes gives you the relative concentrations of those elements).

Does anyone know how to test for a difference between sodium hydrogen carbonate and sodium carbonate?
PH is incredibly useful for NaHCO3 and NaCO3. There's a clear color difference. Sodium Carbonate is incredibly basic, so very dark blue, while NaHCO3 is a medium green. The only pH confusion would be possible with NaHCO3 and NaC2H3O2, but HCl makes that very easy.

Re: Forensics C

Posted: March 11th, 2014, 8:36 pm
by spackenkillkid
Also, does anyone know how powder samples will be provided? I'm assuming small plastic vials.

Re: Forensics C

Posted: March 12th, 2014, 8:35 am
by vxpvm
spackenkillkid wrote:Also, does anyone know how powder samples will be provided? I'm assuming small plastic vials.
I've usually gotten samples in little Ziploc baggies or small plastic containers, but there's always a sufficient amount to do all the tests you need.