Forensics C

[ckenn4189]

Three questions:
1. What is the difference in avian, human, amphibian, and mammalian blood?
2. Can someone walk me through polymerization and the different types such as addition, condensation, etc?
3. According to the rules, participants need to know seeds and pollen from different country regions. What are the most common ones asked for?

[TheRarePinkSheep]

Human and mammalian blood do not contain a nucleus while avian and amphibian do. To distinguish avian from amphibian, check the ratio of the nucleus to the size of the blood cell. Avian blood often has a greater nucleus to cell ratio than amphibian blood.

I was also wondering how to tell pc and pmma apart? Most solution tests go over the other plastics but it seems they are so dense that most of the typically used liquids can't tell them apart? What liquid can tell them apart?

[jaspattack]

I was also wondering how to tell pc and pmma apart? Most solution tests go over the other plastics but it seems they are so dense that most of the typically used liquids can't tell them apart? What liquid can tell them apart?

None of the reagents provided will distinguish between PC and PMMA because their densities are so similar. In a case like that burn test results will likely be provided so that it's possible to distinguish them.

[ckenn4189]

I was also wondering how to tell pc and pmma apart? Most solution tests go over the other plastics but it seems they are so dense that most of the typically used liquids can't tell them apart? What liquid can tell them apart?

None of the reagents provided will distinguish between PC and PMMA because their densities are so similar. In a case like that burn test results will likely be provided so that it's possible to distinguish them.

Well, what are the burn test results for those two and what liquid should be used to measure plastic density? Water, NaCl solution, vegetable oil? Also, what does polymerization by addition, condensation, etc. mean?

[Umaroth]

I was also wondering how to tell pc and pmma apart? Most solution tests go over the other plastics but it seems they are so dense that most of the typically used liquids can't tell them apart? What liquid can tell them apart?

None of the reagents provided will distinguish between PC and PMMA because their densities are so similar. In a case like that burn test results will likely be provided so that it's possible to distinguish them.

Well, what are the burn test results for those two and what liquid should be used to measure plastic density? Water, NaCl solution, vegetable oil? Also, what does polymerization by addition, condensation, etc. mean?

I don't do forensics, but that sounds like some very easily googleable stuff that you could save a lot of time figuring out by doing research rather than waiting for an explanation on a forum.

[ckenn4189]

Well, I have looked up what liquid to use and I can't find anything and I am working on flame tests myself but I am asking about pollen because I have never done Forensics before and Crimbesuters had no seeds or pollen. I want to know about other's experiences with seeds on the test.

[SilverBreeze]

Is anyone else having issues with mass spectrometry? I know I personally need to practice that a lot more, but I'm running into a brick wall when the mass spec asks you to ID without a multiple choice and structures and the answer is something like "heroin," where the answer molecule isn't particularly simple or common and it's not the IUPAC name. Should I just guess on problems like those?

[jaspattack]

Well, I have looked up what liquid to use and I can't find anything and I am working on flame tests myself but I am asking about pollen because I have never done Forensics before and Crimbesuters had no seeds or pollen. I want to know about other's experiences with seeds on the test.

This is going to be a really helpful resource for you. The density reagents and their respective densities are on that page under polymers. Burn test results can be found pretty easily on Google, though - just google "[name of plastic] flame test" and you can usually find pretty good results.

Seeds and pollen are used very infrequently on tests in my experience - usually it's just matching if something was found on the suspect and at the scene of the crime.

As for addition vs. condensation, it's all about how the polymer forms. Addition is formed when the monomers (units of the molecule) are "added" together, and nothing is released as a result. Adding propylene units together equals polypropylene. In condensation, a by-product such as water or ammonia is formed when the units are formed into a polymer. There are other differences too, but that's the gist of it.

[sapfs]

For the competition, is it 2 unique note sheets for 2 participants or do both participants have to use 2 note sheets that have the same information on them?

[jaspattack]

For the competition, is it 2 unique note sheets for 2 participants or do both participants have to use 2 note sheets that have the same information on them?

One unique notesheet per participant - if you have two participants, you can have two unique notesheets.