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Specialty Chemistry Forums => Citizen Chemist => Topic started by: CausticPotash on June 22, 2007, 02:08:30 PM

Title: Why Does Burning Magnesium Not Melt Dry Ice?
Post by: CausticPotash on June 22, 2007, 02:08:30 PM

My friend and I were trying out this experiment we found online where you take two blocks of dry ice and dig a small hole in one. Then you poor some magnesium filings into the hole, ignite the magnesium, and cover it with the other block of dry ice. Then it starts to glow even brighter than magnesium will when burned in air, and it shot a foot long jet of fire out the back. After the reaction, we removed the magnesia and carbon and were suprised to find that the dry ice had barely melted. Does anybody know why?

Title: Re: Why Does Burning Magnesium Not Melt Dry Ice?
Post by: Borek on June 22, 2007, 02:33:14 PM

Have you ever seen dry ice melted?

Title: Re: Why Does Burning Magnesium Not Melt Dry Ice?
Post by: CausticPotash on June 22, 2007, 04:36:00 PM

Oh, sorry I misworded it. I know that dry ice only sublimes, but no more had sublimed than before we burned the magnesium. It looked exactly the same, I was at least expecting a big hole to be made in the stuff.

Title: Re: Why Does Burning Magnesium Not Melt Dry Ice?
Post by: hmx9123 on June 22, 2007, 10:44:53 PM

Perhaps more CO2 was lost than you know.  It's a lot harder to gauge loss of solid sublimation than it is liquid loss by eye.

Title: Re: Why Does Burning Magnesium Not Melt Dry Ice?
Post by: kelaniz on June 27, 2007, 05:00:04 AM

What happens if you blast a block of dry ice with a propane torch? I'd imagine that would be pretty similar.