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Do invitational competitions like Princeton require competitors to identify fibers from actual burn tests?

Stefannli wrote:Do invitational competitions like Princeton require competitors to identify fibers from actual burn tests?

Yes, they should. Candles and matches are not too hard to come by nowadays. Again, tho, that is also dependent on the event supervisor. And, as with hairs, if they're difficult to come by, they will use microscope images as a substitute (a poor substitute, really, but in all honesty, feasibility of obtaining that stuff may not necessarily be in the event supervisor's control either).

Hi Guys,
I'm new to forensics this year, but I've been trying to find the best and most time efficient method for the qualitative analysis. There are just 4 powders that seem to have the same results for all of the tests we are given. The powders I've been having a problem differentiating are Sodium Acetate, Sodium Chloride, Calcium Sulfate, and Magnesium Sulfate. Please let me know how I can differentiate these.

artsygirl34 wrote:Hi Guys,
I'm new to forensics this year, but I've been trying to find the best and most time efficient method for the qualitative analysis. There are just 4 powders that seem to have the same results for all of the tests we are given. The powders I've been having a problem differentiating are Sodium Acetate, Sodium Chloride, Calcium Sulfate, and Magnesium Sulfate. Please let me know how I can differentiate these.

- sodium acetate will smell like vinegar (because it forms some acetic acid) and has a slightly basic pH
- sodium chloride literally doesn't do anything and has a neutral pH. Plus, it's table salt - it's very cubic.
- calcium sulfate doesn't really dissolve in water. Plus, clue: it's Plaster of Paris.
- magnesium sulfate will dissolve in water but form a precipitate when you add NaOH to it.

cc

pikachu4919 wrote:

artsygirl34 wrote:Hi Guys,
I'm new to forensics this year, but I've been trying to find the best and most time efficient method for the qualitative analysis. There are just 4 powders that seem to have the same results for all of the tests we are given. The powders I've been having a problem differentiating are Sodium Acetate, Sodium Chloride, Calcium Sulfate, and Magnesium Sulfate. Please let me know how I can differentiate these.

- sodium acetate will smell like vinegar (because it forms some acetic acid) and has a slightly basic pH
- sodium chloride literally doesn't do anything and has a neutral pH. Plus, it's table salt - it's very cubic.
- calcium sulfate doesn't really dissolve in water. Plus, clue: it's Plaster of Paris.
- magnesium sulfate will dissolve in water but form a precipitate when you add NaOH to it.

Wait, I might have seen you at Princeton! My partner and I represented Charter School of Wilmington B and we got 3rd place in forensics. Thanks for your help on forums!

That message was for Pikachu

Stefannli wrote:

pikachu4919 wrote:

artsygirl34 wrote:Hi Guys,
I'm new to forensics this year, but I've been trying to find the best and most time efficient method for the qualitative analysis. There are just 4 powders that seem to have the same results for all of the tests we are given. The powders I've been having a problem differentiating are Sodium Acetate, Sodium Chloride, Calcium Sulfate, and Magnesium Sulfate. Please let me know how I can differentiate these.

- sodium acetate will smell like vinegar (because it forms some acetic acid) and has a slightly basic pH
- sodium chloride literally doesn't do anything and has a neutral pH. Plus, it's table salt - it's very cubic.
- calcium sulfate doesn't really dissolve in water. Plus, clue: it's Plaster of Paris.
- magnesium sulfate will dissolve in water but form a precipitate when you add NaOH to it.

Wait, I might have seen you at Princeton! My partner and I represented Charter School of Wilmington B and we got 3rd place in forensics. Thanks for your help on forums!

Stefannli wrote:That message was for Pikachu

Yes, I was there. I was the one in the black lab coat with a very loud voice (the EHS guy in the blue lab coat compared it to Frau from Austin Powers, although I’m not quite sure I actually yell like that). And I was also the one trolling with answering all your questions about Princeton Invitational, which I found kinda funny since I was the supervisor, after all. I’m glad you did well!

pikachu4919 wrote:Yes, I was there. I was the one in the black lab coat with a very loud voice (the EHS guy in the blue lab coat compared it to Frau from Austin Powers, although I’m not quite sure I actually yell like that). And I was also the one trolling with answering all your questions about Princeton Invitational, which I found kinda funny since I was the supervisor, after all. I’m glad you did well!

Ah, sadly I don't remember that. Are you a guy or a girl? All I remember was the guy in the blue lab coat that looked like Grant Imahara from the now nonexistent mythbusters. Also, I was the guy with the top knot/very small pony tail w/glasses.

Woops, still not sure how to use the forum features... Also I meant to ask if you were a man or woman, so excuse my disrespectful manner. I'm just trying figure out which of the supervisors was you.