It is my understanding that most of the chemical reactions occure long before the volcano actually erupts and that the eruption is the result of the buildup of pressure in the magma flow seeking an exhaust vent.
While I'm sure there is some chemical reaction as the molten lava passes by different layers in the earth and gas pockets etc... I don't think that these would be measurable unless you knew the exact geology of the earth that the lava passes through on its way out.
There is also the perspective of the effects of the molten lava on the atmosphere it emerges to. If its an under sea eruption I'm sure that there is some steam, hydrogen, and oxygen released and so forth when the water contacts such an extreem heat. If released into the earths atmosphere I would imagine there are some fusing and breaking down of molecular structures in the air as well. This is probably similar to the effect of lightning on our atmosphere which produces 03 (ozone) from the O and O2 (breathable oxygen) molecules the static electricity comes in contact with.
I wish that I did have the technical data you desire as I am working from sheer speculation on this one. I did however find this link you may be interested in:
www.geo.mtu.edu
I haven't read it all but it seemed that it may have your answers after skimming through it.
While I'm sure there is some chemical reaction as the molten lava passes by different layers in the earth and gas pockets etc... I don't think that these would be measurable unless you knew the exact geology of the earth that the lava passes through on its way out.
There is also the perspective of the effects of the molten lava on the atmosphere it emerges to. If its an under sea eruption I'm sure that there is some steam, hydrogen, and oxygen released and so forth when the water contacts such an extreem heat. If released into the earths atmosphere I would imagine there are some fusing and breaking down of molecular structures in the air as well. This is probably similar to the effect of lightning on our atmosphere which produces 03 (ozone) from the O and O2 (breathable oxygen) molecules the static electricity comes in contact with.
I wish that I did have the technical data you desire as I am working from sheer speculation on this one. I did however find this link you may be interested in:
www.geo.mtu.edu
I haven't read it all but it seemed that it may have your answers after skimming through it.