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samlan16 wrote:

drcubbin wrote:Ah yes, I see that. Much appreciated. I was asking because Rule 2. c. iii. states that "the supervisor may provide candle and matches if fibers given." So fibers may be burned during the competition. Am I interpreting this correctly?

Yes, that is correct, and hair may be burned as well.

Depends on the competition grounds. In both Div. B Crimebusters and C Forensics, I've been in situations where a) the particular room on that campus did not allow open flames (which really slowed down flame tests for powders) or b) the proctor didn't read the rules and never requested it. It's helpful to learn multiple identification methods (such as using a microscope, or, if you're desperate, by touch and texture alone) in case the event runners are irresponsible - which doesn't normally happen, but I like to prepare for the worst. Every year, there's always someone who got pulled in at the last minute and has never done something like this before.

My partner and I are feeling really confident about this event based on regionals, and we aren't really sure what to do during practices to get ready for state besides practicing mystery powders and other topics over and over. Does anyone who has had state already have any advice?

Panda Weasley wrote:My partner and I are feeling really confident about this event based on regionals, and we aren't really sure what to do during practices to get ready for state besides practicing mystery powders and other topics over and over. Does anyone who has had state already have any advice?

Hey, I have States coming up in about a week, so I might not be able to give too much advice, but I would suggest practicing more mixtures. Now that we are in States, they can throw in three powder combinations instead of just two, and there will be 2-4 of them. Faster analysis would be better too; the minimum will be 10 powders, which means you need to analyze more in the same time frame AND save time for the analysis.
If the event leaders really wanted to test you, I bet they would throw in talc or something that doesn't have a "stand out quality" into a mixture just to see if you can identify it, but I can't say for sure because I have never gone to state level on Crime Busters before. I live in NC, so our rules are slightly altered in that we only do powders, chromatography and tire tracks/shoe prints. I hope this helps, though!

daydreamer0023 wrote:

Panda Weasley wrote:My partner and I are feeling really confident about this event based on regionals, and we aren't really sure what to do during practices to get ready for state besides practicing mystery powders and other topics over and over. Does anyone who has had state already have any advice?

Hey, I have States coming up in about a week, so I might not be able to give too much advice, but I would suggest practicing more mixtures. Now that we are in States, they can throw in three powder combinations instead of just two, and there will be 2-4 of them. Faster analysis would be better too; the minimum will be 10 powders, which means you need to analyze more in the same time frame AND save time for the analysis.
If the event leaders really wanted to test you, I bet they would throw in talc or something that doesn't have a "stand out quality" into a mixture just to see if you can identify it, but I can't say for sure because I have never gone to state level on Crime Busters before. I live in NC, so our rules are slightly altered in that we only do powders, chromatography and tire tracks/shoe prints. I hope this helps, though!

Ok thanks for this information! Just FYI Talc is not on the list of powders this year. I'm not sure if that was just a slip of mind since it has been previously, but I thought I would go ahead and let you know.

I have a question regarding the mixed powders. My school is unable to provide all of the materials needed for the competition so we can't test the mixed powder reactions. I tried to look around for some sources online, but most of it only covers the one-powder part. If there are two powders I can try to wing it and give an educated guess but on the rules it said "4a. At the state level, teams will have 15-18 unknowns and may have at least two mixtures containing 2-3 of the solids with asterisks." With three powders mix in, you have to be extra precise. Does anyone know any links or pages that can link me to a chart with two-three powders mix? Thank you, help is much appreciated!

vivian_t wrote:I have a question regarding the mixed powders. My school is unable to provide all of the materials needed for the competition so we can't test the mixed powder reactions. I tried to look around for some sources online, but most of it only covers the one-powder part. If there are two powders I can try to wing it and give an educated guess but on the rules it said "4a. At the state level, teams will have 15-18 unknowns and may have at least two mixtures containing 2-3 of the solids with asterisks." With three powders mix in, you have to be extra precise. Does anyone know any links or pages that can link me to a chart with two-three powders mix? Thank you, help is much appreciated!

Honestly, practicing random mixture tests Hands-on is the only way to really master identifying mixtures of any number of powders. In your case though I would suggest that you apply what you already know from single powders to help you ID what is in a mixture. I doubt there is any kind of accurate graph describing what a mixture would do so this is likely your only way of getting past mixtures. An example of applying single power reactions to a mixture would be, if you had a potential mixture of 3 that reacts to HCl and Iodine, then you can deduce that there is most likely flour/cornstarch for the Iodine to react, and baking soda, calcium carbonate (limestone), or alka seltzer causing the HCl to react. Your third powder could be any of the previously mentioned, or possibly gypsum or a grain. It really all comes down to how well you know how each substance reacts to each reagent, and how they look. Baking soda usually has a very fast and bubbly reaction while calcium carbonate has a very foamy and slower reaction. Another thing you can do is pour some of the mixture onto a towel or spot plate cover and, using any type of stick or rod, slowly flattening out the mixture allowing you to see some individual particles or grains from the mixture. You are correct that you need to be extra precise, but don't always jump to the conclusion that a mixture is 3 substances, since the test usually doesn't state how many powders are in each mixture. Good Luck at state, if you have any other questions feel free to ask. Hoped this helped you out

Thanks ssb4ever! I'll definitely keep that in mind for my state competition.