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Author Topic: Curious mercury reaction from years ago  (Read 1159 times)

Offline strata

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Curious mercury reaction from years ago
« on: 14/02/2014 14:39:19 »
I'm not advocating playing with mercury - in fact don't play with mercury but many moons ago we were allowed to and over a lunchtime conversation today I remember one demo that was never explained.

We had a trough of water with about 10ml of mercury in one blob and an orange powder. When a dollop of orange powder was added to the water, the mercury would rush towards the powder and react producing a greenish product and sending blobs of mercury shooting off in all directions. The reaction could be repeated several times before the water got murky

The teacher refused to tell us what the orange powder was.

I never plan to repeat it but I'd love to know what it was, all I could guess at was some sort of chromium compound and it might not have been plain water.



 

Offline chiralSPO

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Re: Curious mercury reaction from years ago
« Reply #1 on: 14/02/2014 14:46:36 »
This demo sounds like the "mercury beating heart" (http://en.wikipedia.org/wiki/Mercury_beating_heart)

Potassium dichromate (K2Cr2O7; http://en.wikipedia.org/wiki/Potassium_dichromate) is bright orange, and when dissolved in sulfuric acid, is a possible component of this demo (KMnO4 also works well)
 

Offline strata

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Re: Curious mercury reaction from years ago
« Reply #2 on: 17/02/2014 08:25:28 »
Cheers, I'm wondering if the trough it was done in was iron which would neatly fit. I'm also eyeing up that pot of mercury in the fume hood and resisting temptation...
 

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Re: Curious mercury reaction from years ago
« Reply #2 on: 17/02/2014 08:25:28 »

 

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