Magnesium fire, reaction with water

Hi,

I need some help or explanation.

What cause magnesium to explode when set on fire and water is sprayed on it. Is there a solution or chemical product or additive that can be added to water to prevent those small explosion.

Any help would be greatly appreciated

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I don't think it "explodes"; 2 Mg + O[sub]2[/sub] > 2MgO; 2MgO + H[sub]2[/sub]O > 2Mg(OH); that is, from this reaction you will get milk of magnesia; there is nothing explosive there; however, burning magnesium produces intense amounts of UV light (NEVER look at the intense pearly white flames of burning Mg) and heat; I suspect the "explosion" is the vaporization of the water, which will splash back on you and scald you and perhaps spray you with particles of burning magnesium. :(

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Hmm

The explosion is *not* due to

Mg + 2.H2O >> Mg(OH)2 + H2(g)

but *is due* to

2.H2(g) + O2(g) >> 2H2O(g) + HEAT

The HEAT causes expansion of surrounding air and therefore an explosion.

Anyone heard of a H bomb?

You cannot really stop the explosion but you can prevent it by avoiding contact of water with magnesium (e.g. do not spray it when it's burning). More reactive metals such as sodium are stored in an organic compound to prevent such reactions with water (and also oxygen).

Re: Hmm

[quote="halfaquark"]The explosion is *not* due to

Mg + 2.H2O >> Mg(OH)2 + H2(g)

but *is due* to

2.H2(g) + O2(g) >> 2H2O(g) + HEAT

The HEAT causes expansion of surrounding air and therefore an explosion.

Anyone heard of a H bomb?

You cannot really stop the explosion but you can prevent it by avoiding contact of water with magnesium (e.g. do not spray it when it's burning). More reactive metals such as sodium are stored in an organic compound to prevent such reactions with water (and also oxygen).[/quote]

2H[size=8]2[/size] + O[size=8]2[/size] -> 2H[size=8]2[/size]O
is an implosion, is it not?

Also, that has NOTHING to do with the H bomb!

Details of the H-bomb (thermonuclear weapon) can be found here:
http://www.ccnr.org/Howard_Morland.html

WebElements: the periodic table on the WWW [http://www.webelements.com/]

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