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Topic: Yellow solution?  (Read 4720 times)

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Offline Sophia7X

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Yellow solution?
« on: November 08, 2012, 10:13:00 PM »
I was making H2 gas in a flask with a stopper and tubing connected to a balloon. I used HCl and Al, when the reaction proceeded, the mixture was grey. Then the next day, it was a clear, bright yellow. I left the stopper on... wondering what could have caused this?
Entropy happens.

Offline billnotgatez

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Re: Yellow solution?
« Reply #1 on: November 09, 2012, 05:27:23 AM »
From WIKI
Aluminium chloride (AlCl3)
 Appearance white or pale yellow solid, hygroscopic

It is white, but samples are often contaminated with iron trichloride, giving it a yellow colour.



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Remember that you initially had AL, HCl, some Air, Water (can we assume pure) in your flask.

« Last Edit: November 09, 2012, 05:46:52 AM by billnotgatez »

Offline Arkcon

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Re: Yellow solution?
« Reply #2 on: November 09, 2012, 06:45:30 AM »
This really depends on how pure you aluminum was.  If you bought pellets from a chemical supplier, fine.  But if you wadded up household aluminum foil (this post is in Citizen chemist,) then the aluminum is very impure.  Also, I'd notice, when I was playing with muriatic acid that I'd purchased from the hardware store, that it is likewise impure, and yellows on exposure to air.
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Offline Borek

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Re: Yellow solution?
« Reply #3 on: November 09, 2012, 12:04:12 PM »
Stopper would be my first guess.
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Offline Sophia7X

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Re: Yellow solution?
« Reply #4 on: November 09, 2012, 04:44:41 PM »
Not sure about the aluminum being the reason since it took a while for the color to change to yellow... maybe it was the HCl.

How would a stopper turn something yellow?
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Offline Borek

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Re: Yellow solution?
« Reply #5 on: November 09, 2012, 05:35:11 PM »
Something could be leached out of the material.

Unless it was a glass stopper.
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