Forensics C

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SilverBreeze
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Re: Forensics C

Post by SilverBreeze »

Crime/Forensics writers: please please please say what a reaction is (e.g. "fizzes"), not just whether it reacted (e.g. "yes").
Odor and precipitation are different. Turning orange and turning blue are different.

EDIT: Also, please don't do the "each row has a mistake; find the mistake" thing. A lot of times when the results contradict themselves, students end up having to go off pH, which is not reliable when you can't do the lab yourself. Even if it's technically possible to solve, it's contrived and doesn't make me love science more.
Before someone tells me "it's realistic and you make mistakes in the lab," it's not the same thing. I know which tests I'm likely to mess up and which ones I am not. I'm probably not going to mistake a lilac flame for a red one, or think the solution turned dark blue when it didn't. I might mess up pH or sometimes solubility, and sodium contamination can make a flame turn yellow, so I trust those tests less.
Last edited by SilverBreeze on February 25th, 2021, 9:11 am, edited 2 times in total.
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Re: Forensics C

Post by sciolyperson1 »

Hi all!

We're running Forensics for this month's SMEC! To learn more, head over to our forums thread and register at the google form here!
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Re: Forensics C

Post by learner2 »

Hi! Do you guys know if calcium nitrate and NaOH form a precipitate? I know that magnesium sulfate and NaOH definitely forms a precipitate, but I'm not sure about calcium nitrate.
If not, what I can use to identify these two powders?
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Re: Forensics C

Post by pikachu4919 »

learner2 wrote: June 5th, 2021, 5:55 pm Hi! Do you guys know if calcium nitrate and NaOH form a precipitate? I know that magnesium sulfate and NaOH definitely forms a precipitate, but I'm not sure about calcium nitrate.
If not, what I can use to identify these two powders?
Yes, calcium nitrate does precipitate with NaOH.
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