On Oct 3, 3:46 pm, Weatherlawyer wrote:
On Oct 3, 12:06 pm, Nosterill wrote:





On Oct 3, 10:57 am, Weatherlawyer wrote:

On Oct 3, 12:35 am, "RyderCup&PrezCupSux"

wrote:
Hello,

I know that most volcano movies are crap as far as real science is
concerned. I have a question about one specific scenario in "Dante's Peak".
Some people get trapped in a metallic boat on an acidic lake. Boat starts
dissolving as it is proceeding on the lake and water starts to come into
the boat. The propellers dissolve in the acidic water stranding the boat in
the lake.

How realistic, if at all, is that scenario?

What acid would be involved? The only one I can think of is carbonic
acid. Sulphur will burn in oxygen to form sulphur dioxide but getting
that to form an acid is rather difficult. Maybe there are life forms
in the earth that will convert sulphur into sulphuric acid.

Sulphur dioxide forms an acid very easily by dissolving in water to
produce the relatively weak sulphurous acid (H+ HSO3-). This is a
reducing acid and not too tough on metals. Sulphur dioxide can "burn"
in excess oxygen to produce the trioxide which dissolves in water to
produce the far more aggressive oxidising sulphuric acid and then, if
all the water molecules have been used, it continues to dissolve
producing something variously called fuming sulphuric acid or oleum.
That stuff is truly viscious and would certainly make short work of
most metals - however! I don't imagine that would happen "in the
wild". Far more probable is the bacterial theory and there are plenty
of examples. Villa Luz cave in Mexico is a classic case. This too is
unlikely to occur in an above ground lake in a realistic timescale.

So - in summary - there are ways of making boat eating acid from
sulphur but not in the scenario presented in the film.

Nice try but I actually looked the chemistry up for a thread in a
meteorology discussion on glowballs.

According to a somewhat dated text book used in schools to teach 16
and 17 year olds when I were a lad, the gas sulphur dioxide hadn't
been turned into an acid by dissolving in water.

Wow! That must be dated. Does it mention phlogiston? We were making
sulphurous acid in the school chemistry lab nearly forty years ago.
H2O + SO2 - H+ + HSO3- (H+ is the definition of acid btw). This is
basic O level chemistry but since you are an unbeliever, here is a
link http://en.wikipedia.org/wiki/Sulfurous_acid

Before you jump on molecular H2SO3 not existing out of solution, that
doesn't change the fact that SO2 in water produces an acid solution.
The same applies to carbonic acid and that accounts for most cave
systems.