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General => General Technical Chat => Topic started by: Sionyn on December 24, 2012, 07:20:19 pm

Title: Please Sir I Don't Want Any More
Post by: Sionyn on December 24, 2012, 07:20:19 pm
forget the rubbish in can ever seen a self heating can before ?
any clues what chemical reation is going on here ?

CaO(s)+ H2O(l) ? Ca(OH)2(s)
Copper sulfate and powdered zinc can also be used, but to lesser effect:
CuSO4(s) + Zn(s) ? ZnSO4(s) + Cu(s)

Christmas Dinner in a Can | Ashens (https://www.youtube.com/watch?v=K-mfYXdjNTM#ws)


bonus tricks
http://www.guardian.co.uk/science/blog/2012/dec/21/christmas-dinner-chemistry-party-tricks (http://www.guardian.co.uk/science/blog/2012/dec/21/christmas-dinner-chemistry-party-tricks) 
Title: Re: Please Sir I Don't Want Any More
Post by: M0BSW on December 24, 2012, 08:09:36 pm
 I suppose if you lived on your own and felt sorry for yourself,  it's hot and  hmmmmmmmmmmmmmmmmmmmmmmmm :palm:
Title: Re: Please Sir I Don't Want Any More
Post by: G7PSK on December 24, 2012, 10:28:20 pm
That looks like someone has already eaten it already, then had a few too many.
Title: Re: Please Sir I Don't Want Any More
Post by: grumpydoc on December 24, 2012, 10:54:47 pm
Don't understand why anyone would bother unless they want to eat it in the middle of a field or other location away from any available heat source.

I'd have thought that a ready meal from <insert name of your favourite supermarket chain> would be a) probably cheaper, b) less hassle and c) actually taste better (although I normally struggle to think of anything that would taste worse than a supermarket ready meal, I think this might be it).

Title: Re: Please Sir I Don't Want Any More
Post by: free_electron on December 25, 2012, 12:41:48 am
oh my... this classifies as one of these foods where there is no telling what it looked like when it was still alive... pig ? cow ? hore ? dog ? cat ? racoon ? skunk ? your guess is a s good as mine...
Title: Re: Please Sir I Don't Want Any More
Post by: Hypernova on December 25, 2012, 01:46:05 am
oh my... this classifies as one of these foods where there is no telling what it looked like when it was still alive... pig ? cow ? hore ? dog ? cat ? racoon ? skunk ? your guess is a s good as mine...


1 vote down for random hobo off the street who happened to walk by the factory gate.
Title: Re: Please Sir I Don't Want Any More
Post by: ee851 on December 25, 2012, 02:04:27 am
It's for homeless people.
Title: Re: Please Sir I Don't Want Any More
Post by: ftransform on December 25, 2012, 02:54:12 am
I think its pretty cool. Not as yummy as my chirstmas turkey but the reaction is cool.

electronics and chem geeks don't get along do they? ::)

the reviewer sounds annoying.
I always end up making a stew like that out of the leftover turkey bits. Usually its fairly tasty. That or I mix with salsa and make a mexican version of that.

What does this man expect of canned food? The best "chirstmas" dinner I can come up with using canned food is a DAK canned ham with brown sugar and cloves on it.
I gotta buy a few of those lol.
Title: Re: Please Sir I Don't Want Any More
Post by: SeanB on December 25, 2012, 04:54:53 am
MMMMMM, Rat packs..................
Title: Re: Please Sir I Don't Want Any More
Post by: Simon on December 26, 2012, 11:45:01 pm
Now I'm no cook but in 10 minutes can cook a steak in a pan and lightly boil some green beans.
Title: Re: Please Sir I Don't Want Any More
Post by: nixxon on December 27, 2012, 12:11:42 am
If we can forget about the food inside the can for a while: what chemistry made the increase in temperature? It looked like a pretty exothermic reaction going on...
Title: Re: Please Sir I Don't Want Any More
Post by: westfw on December 27, 2012, 01:42:21 am
Self-heating cans based on calcium silicide and iron oxide date back to WWII.  Following wikipedia links, it looks like modern reactions are based on Magnesium/Water reactions with iron and salt as "helpers."  Generates about 310 calories/g.   (ah.  That probably explains why CaSi2 is so hard to get these days...

http://en.wikipedia.org/wiki/Self-heating_food_packaging (http://en.wikipedia.org/wiki/Self-heating_food_packaging)