There is plenty of SO2 gas which can react with water to produce sulfurous acid, H2SO3. If SO2 get oxidized to SO3, that reacts with H2O to produce H2SO4 but I don't think that usually happens. Here is a web site that gives the common gases.
http://en.wikipedia.org/wiki/Volcanic_gas
can some one tell does composites produce a sulfuric acid when it erupts or does any volcanoes produce sulfuric acid
please help urgent
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