What determines whether a substance can be ignited or not?
What determines whether a substance can be ignited or not?
What determines whether a substance can be ignited or not?
What determines whether a substance can be ignited or not?
Quantitatively, change of Gibbs potential, G=H-TS, is used to estimate possibility of a chemical reaction under given conditions.What determines whether a substance can be ignited or not?
Everything is flammable.
Even water?
You should see what happens when you throw water on a burning hunk of magnesium.
In fairness though, the water isn't burning. It's being dissociated by the extreme heat of the burning Mg and then explosively recombining into H2O. Umm... Right?
And thenNo, the water reacts directly with the heated magnesium to form Magnesium Hydroxide and hydrogen gas, and the hydrogen gas then reacts with the air.
$$Mg + 2H_2O \rightarrow Mg(OH)_2 + H_2$$
And then
$$2H_2 + O_2 \rightarrow 2H_2O$$
It looks like half of the water molecules serve as catalysts, since they exist at both the start and end of the cycle of reactions? And the hydrogen is merely an intermediate result that quickly vanishes. So, ultimately (and rather quickly I assume)...
$$2Mg + 4H_2O + O_2 \rightarrow 2Mg(OH)_2 + 2H_2O$$