Hmmm ... well not all forms of any of the powders are the same ... so that could be a factor. Also, Ca(NO3) has an orange flame test that gives off sparks, unlike MgSO4 that does not burn, but may give off water vapor.poparteeb2 wrote:Can anyone help me with the two powders that are supposed to form precipitates w/ NaOH?
Calcium nitrate and magnesium sulfate? I think I have really bad samples at school or something, because neither of them are forming precipitates.
And how do you tell the difference between the two if you don't have a flame test? Do they react differently with the reagents given or have different pH? Or do the precipitates look different?
Sorry it's a lot of questions! I'll be really glad if anyone with Forensics experience can help out
Check out the wiki page for Forensics. http://scioly.org/wiki/index.php/Forensics#Polymerscomputergeek3 wrote:Does anyone know what the most commonly used density solutions (for plastic ID) are?
Common liquids used to test plastic densities include water, vegetable oil, isopropyl alcohol, and NaCl solution (10%, 25%, and saturated).
The two major features for hair ID are the medulla and cuticle pattern.Skyrenify wrote:I was wondering how one would do hair follicle analysis because we had it in states last year and my teammate and I didn't know how to find out which organism it belonged to. I'm trying to cover all my bases so I will be able to avoid being dumbfounded during the event. Last year went well, but really want to make a place for my High School this year.
Ahh thank you!JustDroobles wrote:The two major features for hair ID are the medulla and cuticle pattern.Skyrenify wrote:I was wondering how one would do hair follicle analysis because we had it in states last year and my teammate and I didn't know how to find out which organism it belonged to. I'm trying to cover all my bases so I will be able to avoid being dumbfounded during the event. Last year went well, but really want to make a place for my High School this year.
Human hair has a thin and often non-continuous medulla and an imbricate cuticle pattern.
Dog hair has a thick medulla and an imbricate scale pattern.
Cat hair has spinous cuticle pattern.
Bat hair has a coronal cuticle pattern.
If you don't know what any of these terms mean, they should be easily Google-able.
No problem! And I know how you feel, I got 2nd place in Forensics my junior and senior year... I was actually super excited junior year because the highest placing I had gotten throughout the season was a 4th place at an invitational. However, after getting several invitational golds my senior year I was hoping for that tiny improvement at state. I hope you get that elusive gold this year!Skyrenify wrote:Ahh thank you!JustDroobles wrote:The two major features for hair ID are the medulla and cuticle pattern.Skyrenify wrote:I was wondering how one would do hair follicle analysis because we had it in states last year and my teammate and I didn't know how to find out which organism it belonged to. I'm trying to cover all my bases so I will be able to avoid being dumbfounded during the event. Last year went well, but really want to make a place for my High School this year.
Human hair has a thin and often non-continuous medulla and an imbricate cuticle pattern.
Dog hair has a thick medulla and an imbricate scale pattern.
Cat hair has spinous cuticle pattern.
Bat hair has a coronal cuticle pattern.
If you don't know what any of these terms mean, they should be easily Google-able.
Might be able to get that elusive 1st place this year.
Still beating myself up for mixing up common blood types last year at states. Got us 4th place T^T
Anyhow, thank you very much
Haha thanks!JustDroobles wrote: No problem! And I know how you feel, I got 2nd place in Forensics my junior and senior year... I was actually super excited junior year because the highest placing I had gotten throughout the season was a 4th place at an invitational. However, after getting several invitational golds my senior year I was hoping for that tiny improvement at state. I hope you get that elusive gold this year!
