Ask A Scientist Chemistry Archive

  
name         Todd
status       educator
grade        9-12
location     NV

Question -   Is it possible to break up CO2 into its components by 
introducing magnesium + heat to first produce 2MgO and C then scavenge 
the O by bringing H2 in contact with the MgO + heat to produce Mg + H2O?
---------------------------------------------------
DANGER. EXTREMELY HAZARDOUS. DO NOT TRY THIS UNDER ANY CIRCUMSTANCES.

     Yes, burning Mg will reduce CO2 to C + 2MgO. However, this is a
pyrophoric reaction and extremely exothermic. As a result it is impossible
to extinguish a metal Mg fire with CO2. The only way is to use sand, which
just adds heat capacity to cool the fire below the ignition temperature.
Once the CO2 + Mg fire gets started side reactions with oxygen from the air
(and reaction with H2O vapor to produce H2, which then explodes).

Vince Calder
=====================================================