Crime Busters B

[Anapolis]

however, couldn't it possibly used as a nicer more logical connection in analysis? but if the es justs puts like a random synthetic like acrylic and expects u to draw a connection to polyester, then its an oof

You could just assume that if you find a synthetic fiber it would match with any synthetic fibers found on the suspects... i mean.... you could find specifics i guess...... idk lol

[drcubbin]

One of the archived Crime Busters tests (The Case of the Missing Kandinsky) states for the chromatography portion that "if they have attached the same sample in both DI and ISO, give one more point". What id DI and ISO? DIstilled water and ISOpropyl alcohol? Feeling a little foolish that I do not see what must be obvious

[shrewdPanther46]

basically... deionized water and isopropyl

[drcubbin]

basically... deionized water and isopropyl

Thanks. I've supervised a few events, but never Crime Busters. Do they always provide both provide water and isopropol alcohol at stations?

[dholdgreve]

Not usually... Nothing says they can't, but usually it is just distilled water. FWIW, using the same ink can provide SUBSTANTIALLY differing results with the different solvents. Even if the ink is soluble with both, the color fractionalization can be totally different.

[drcubbin]

Not usually... Nothing says they can't, but usually it is just distilled water. FWIW, using the same ink can provide SUBSTANTIALLY differing results with the different solvents. Even if the ink is soluble with both, the color fractionalization can be totally different.

Much appreciated!

[strawberryy]

is it possible to get diff tests in the comp?

[strawberryy]

is it possible to get diff tests in the comp?

[drcubbin]

is it possible to get diff tests in the comp?

If you mean that different teams will get different tests at the same event, I don't believe so. It enough to make up one test per event

[dholdgreve]

is it possible to get diff tests in the comp?

On the other hand, if your question is " Is it possible to be provided (DENSITY) DIFFERENTIAL tests in the competition?" the answer is yes. The Event Coordinator may provide various density liquids using blends of saltwater, alcohol, or cooking oil... even high fructose corn syrup... each has a different specific gravity or density that can be used to identify various polymer unknowns. Due to competition time constraints, I've always carefully massed my density liquids ahead of time, and labeled them with the specific gravity, but I heard of competitions that don't do this, and require the kids to determine the SG of each liquid so they can then test their polymers.

BTW, the density solutions containing alcohol, are difficult to control. If the lid gets left off, the alcohol can vaporize, concentrating the heavier water... so the SG may be slightly higher as the day goes on...