Crime Busters B
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Re: Crime Busters B
How do you separate two powders that are mixed together? ex. baking soda and calcium carbonate
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Re: Crime Busters B
A good explanation for this is in the wiki. Generally, I just look for distinguishable properties from multiple powders.ashleybrown5 wrote:How do you separate two powders that are mixed together? ex. baking soda and calcium carbonate
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!
Re: Crime Busters B
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?
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Re: Crime Busters B
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?
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Re: Crime Busters B
You probs have some old, old peroxide. Spontaneous decompositionknowthewrightstuff wrote: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?
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Re: Crime Busters B
Thanks for the advice. We did notice that our bottle was expired last year so we bought a new bottle, but we still had the same problem. Do you just use a plastic test tube to shake it in?shrewdPanther46 wrote:You probs have some old, old peroxide. Spontaneous decompositionknowthewrightstuff wrote: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?
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Re: Crime Busters B
One way to tell them apart is to put some iodine in it. If it fizzes, it's hydrogen peroxide. If not, water.knowthewrightstuff wrote: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?
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Re: Crime Busters B
The Society of Plastics Engineers sells a pretty comprehensive kit called Hands-On Plastics that has most everything except PMMA. A cheap way to get fibers is to go to the local craft/fabric store and see if they'll let you have 1-inch samples of fabrics for free or for really cheap.SOCoach wrote: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?
I'm not sure how you got that to happen bc if you try to write a balanced equation for it, you won't get a product that will be in gaseous form.Tailsfan101 wrote:One way to tell them apart is to put some iodine in it. If it fizzes, it's hydrogen peroxide. If not, water.knowthewrightstuff wrote: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?
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Purdue BioE '21? reevaluating my life choices
Nationals 2016 ~ 4th place Forensics
"It is important to draw wisdom from different places. If you take it from only one place, it becomes rigid and stale." -Uncle Iroh
About me || Rate my tests!
Opinions expressed on this site are not official; the only place for official rules changes and FAQs is soinc.org.
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Re: Crime Busters B
I found something on the H2O2/KI reaction here.pikachu4919 wrote:I'm not sure how you got that to happen bc if you try to write a balanced equation for it, you won't get a product that will be in gaseous form.Tailsfan101 wrote:One way to tell them apart is to put some iodine in it. If it fizzes, it's hydrogen peroxide. If not, water.knowthewrightstuff wrote: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?
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