Stable Isotope Geochemistry


Options: Use Forum View

Use Monospaced Font
Show Text Part by Default
Show All Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
"BLATTNER, PETER" <[log in to unmask]>
Reply To:
Stable Isotope Geochemistry <[log in to unmask]>
Tue, 21 Oct 1997 11:26:06 +1200
text/plain (31 lines)
Dear Georges and others

Georges Beaudoin mentions the freezing and thawing of BrF-5 in a
Kel-F finger. This reminds me of a time (years ago!) when we
froze some BrF-5 and impatiently hurried up the thawing with a
warm water bath. My intuition got me to move around the corner
and finish something else meanwhile, and after some minute I
heard this eerie sound that proved to emanate from the same water
bath. With or without safety glasses everything LOOKED allright,
so I removed the beaker. In fact the bottom of the Kel-F finger
had cracked parallel to the (rectangular) inner cut-off, and
there was this beautiful slow, uncontrolled but musical reaction
between what was inside and what had been outside. For those who
don't know, a few ml BrF-5 in water could have produced a nice
bang plus poison gas cloud. Before then the finger had performed
excellently for years. Since that experience:

 - we NEVER freeze the Kel-F all the way to liq. N-2, only as
cold as necessary to get the distillation going (which is a great
deal less), and
 - we NEVER put a water bath around the Kel-F containing BrF-5
(This precaution should have been self-evident, but I guess we
looked at Kel-F as a miracle material).

As there will always be impatience, and the belief in miracle
materials, that's my penny's worth.


[log in to unmask]