Crime Busters B

[pikachu4919]

Crime Busters B: Given a scenario, a collection of evidence, and possible suspects, students will perform a series of tests that along with other evidence will be used to solve a crime.

Crime Busters Wiki

Recommended Lab Equipment List for Div. B

Past Threads: 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019

Past Question Marathons: 2015, 2016, 2017, 2018, 2019

[YanaB]

Hi, I was wondering if anyone would like to trade for Crime Busters? I am currently working on a test and have some notes. Also, I was wondering how do people get all of those google drives filled with tests through trading?

[Raiderboy10]

In the 2019 rules it says each participant may bring one paper. Does that mean each team can have 2 different papers or that you can bring 2 of the same one?

[knightmoves]

In the 2019 rules it says each participant may bring one paper. Does that mean each team can have 2 different papers or that you can bring 2 of the same one?

Each human may have one sheet of paper. If your team only has one person doing the event, you get one piece of paper. If your team has two people, they get one piece each. They can be different.

(I'm not a fan of this rule. Small teams are already disadvantaged by having fewer people. Giving them less information as well is just rubbing it in.)

[NewSciolyer]

I don't think the rule was intentionally meant that way. The way they worded doesn't seem like they're explicitly trying to convey that you can have 2 different pieces of paper.

[pathfinder05]

I've been having trouble finding the reactions of the white powders and potassium iodide. I really have no way to test them out myself, so can someone help me out?

[wec01]

I've been having trouble finding the reactions of the white powders and potassium iodide. I really have no way to test them out myself, so can someone help me out?

Iodine is mainly for cornstarch, which will very distinctively turn a dark blue/black, and to distinguish between sodium carbonate and sodium bicarbonate, as sodium carbonate will turn clear with the iodine. For me, I found it’s easiest to see this if you first dissolve the sodium carbonate in water and then add iodine. Other than cornstarch and sodium carbonate there isn’t much other use for it though.

[jimmy-bond]

I've been having trouble finding the reactions of the white powders and potassium iodide. I really have no way to test them out myself, so can someone help me out?

Cornstarch and flour turn it either black or really dark blue. Vitamin C clears. Alka Seltzer fizzes. Calcium carbonate makes it a mustardy-peanut butter color.

[dholdgreve]

I've been having trouble finding the reactions of the white powders and potassium iodide. I really have no way to test them out myself, so can someone help me out?

Iodine is mainly for cornstarch, which will very distinctively turn a dark blue/black, and to distinguish between sodium carbonate and sodium bicarbonate, as sodium carbonate will turn clear with the iodine. For me, I found it’s easiest to see this if you first dissolve the sodium carbonate in water and then add iodine. Other than cornstarch and sodium carbonate there isn’t much other use for it though.

OK, so... point of clarification... Sodium Bicarbonate is Baking Soda, and does not react with Iodine at all, only hydrochloric acid. We do not use Sodium Carbonate in Crimebusters, as it has the potential of being dangerous if mixed with the wrong chemicals. Maybe you were thinking of Ascorbic Acid (Vitamin C). When mixed with potassium Iodide, it will turn the iodide clear. Iodide will turn any starch a very dark blue / black. This would include cornstarch and flour.

[FiveW's]

I've been having trouble finding the reactions of the white powders and potassium iodide. I really have no way to test them out myself, so can someone help me out?

Iodine is mainly for cornstarch, which will very distinctively turn a dark blue/black, and to distinguish between sodium carbonate and sodium bicarbonate, as sodium carbonate will turn clear with the iodine. For me, I found it’s easiest to see this if you first dissolve the sodium carbonate in water and then add iodine. Other than cornstarch and sodium carbonate there isn’t much other use for it though.

OK, so... point of clarification... Sodium Bicarbonate is Baking Soda, and does not react with Iodine at all, only hydrochloric acid. We do not use Sodium Carbonate in Crimebusters, as it has the potential of being dangerous if mixed with the wrong chemicals. Maybe you were thinking of Ascorbic Acid (Vitamin C). When mixed with potassium Iodide, it will turn the iodide clear. Iodide will turn any starch a very dark blue / black. This would include cornstarch and flour.

Also, only white powder that fizzes in Potassium Iodide is Alka-Seltzer. In case it hasn't been stated yet.