Crime Busters B

[Polarrr]

For any competitors doing Crime Busters:

I've done quite a bit of event supervising for Forensics, and I did supervise Crime Busters once since I also had Forensics to supervise at the same tournament, but I'm really not all that experienced in that since my school district did not have Division B SciOly, and while Crime Busters is the Division B parallel of Forensics, there were still quite some significant differences that were not the easiest to adjust to when I first tried running Crime Busters.

If any of competitors who are currently doing Crime Busters or have competed in it in the past would like to offer me some suggestions for what I can do to be an effective event supervisor for it based on their experiences from competing in it, I would absolutely love to hear them, as I would like to make sure I can run whatever events I get assigned to run to the best of my ability!

I used to compete for Division B Crime Busters and have taken many tests. One thing event supervisors always need to do is check the materials the students are bringing in; make sure only the allowed items are being brought in. Also, when creating a crime scene, make sure to give some motives or extra background to certain suspects; don't always state what physical evidence or powders/liquids/metals are on them (ex: one suspect works at a bakery, therefore, if flour or cornstarch is found at the scene, it could be related to this suspect). Finally, always make sure to provide enough materials needed to make sure that the test runs smoothly. I've been to some invitationals where they don't have enough HCl or chromatography paper, and they were simply unprepared, resulting in a very inefficient testing process.

[Birdmusic]

Hi, I'm new to this event (and chemistry in general), so I have a couple of questions.

1) When my partner and I mixed iodine with flour mixed with water or cornstarch mixed with water, it didn't turn dark blue, any ideas why? We tried increasing the amount of water, flour/cornstarch, and iodine, but nothing happened still.

2) If one powder in a mixture dissolved and another didn't, how would you know? Wouldn't the water just be cloudy if one dissolved? Also, how would you know whether only one thing reacted with the HCl and iodine or both reacted?

[shrewdPanther46]

Hi, I'm new to this event (and chemistry in general), so I have a couple of questions.

1) When my partner and I mixed iodine with flour mixed with water or cornstarch mixed with water, it didn't turn dark blue, any ideas why? We tried increasing the amount of water, flour/cornstarch, and iodine, but nothing happened still.

2) If one powder in a mixture dissolved and another didn't, how would you know? Wouldn't the water just be cloudy if one dissolved? Also, how would you know whether only one thing reacted with the HCl and iodine or both reacted?

1. you have to use Potassium Iodide
2. A substance won't dissolve instantly, it takes time

If you have any more questions, be free to ask!

[Unome]

Hi, I'm new to this event (and chemistry in general), so I have a couple of questions.

1) When my partner and I mixed iodine with flour mixed with water or cornstarch mixed with water, it didn't turn dark blue, any ideas why? We tried increasing the amount of water, flour/cornstarch, and iodine, but nothing happened still.

2) If one powder in a mixture dissolved and another didn't, how would you know? Wouldn't the water just be cloudy if one dissolved? Also, how would you know whether only one thing reacted with the HCl and iodine or both reacted?

1. you have to use Potassium Iodide
2. A substance won't dissolve instantly, it takes time

If you have any more questions, be free to ask!

IKI solution

[Birdmusic]

Hi, I'm new to this event (and chemistry in general), so I have a couple of questions.

1) When my partner and I mixed iodine with flour mixed with water or cornstarch mixed with water, it didn't turn dark blue, any ideas why? We tried increasing the amount of water, flour/cornstarch, and iodine, but nothing happened still.

2) If one powder in a mixture dissolved and another didn't, how would you know? Wouldn't the water just be cloudy if one dissolved? Also, how would you know whether only one thing reacted with the HCl and iodine or both reacted?

1. you have to use Potassium Iodide
2. A substance won't dissolve instantly, it takes time

If you have any more questions, be free to ask!

Hi, thank you for responding. We are using potassium iodine, sorry for not being clear.

[ashleybrown5]

How do you separate two powders that are mixed together? ex. baking soda and calcium carbonate

[shrewdPanther46]

How do you separate two powders that are mixed together? ex. baking soda and calcium carbonate

A good explanation for this is in the wiki. Generally, I just look for distinguishable properties from multiple powders.

I have a question pertaining to the analysis "questions" that are generally asked at the end. Is it necessary to write in full sentences, or can a list be presented? Most test have an open ended question and a bunch of lines underneath (like nationals). Could someone please let me know if a list could be used (mainly at higher level competitions) ? I am aware that this could vary between supervisors, but I would like to know the general consensus.

Thanks!

[SOCoach]

Several years ago I bought a polymer / fiber kit for crimebusters that was really good. I can't seem to remember or find where I bought it from. Does anyone have a good site for getting fibers and plastics for crimebusters?

[knowthewrightstuff]

My team has had trouble identifying the difference between water and hydrogen peroxide since they are both odorless and have the same pH. We have tried shaking them and looking for bubbles, but both liquids bubble for us. Are there other methods we could try to effectively identify the difference between these liquids?

[shrewdPanther46]

My team has had trouble identifying the difference between water and hydrogen peroxide since they are both odorless and have the same pH. We have tried shaking them and looking for bubbles, but both liquids bubble for us. Are there other methods we could try to effectively identify the difference between these liquids?

You probs have some old, old peroxide. Spontaneous decomposition