[sdiy] Microwave Ferric Chloride

[Paul Perry]

At 05:51 PM 12/01/04 +0800, Chris Williams wrote:
>Isn't heating water in a microwave dangerous? I seem to remember
>something about the possibility of the water rapidly boiling over 

That is very true. What happens is the liquid might become 'superheated',
that is to say reaches more than 100 deg C (the boiling point, although
a solution will be somewhat higher) and then, it can suddenly and
violently boil over, or indeed explode. In the chem lab this is called
'bumping'.
The way to overcome it, is to put a chunk of terracotta pot in the 
liquid to act as a nucleus for the bubbles to form. It is much likelier
to happen with reheated solutions, because dissolved gases act as 
nuclei otherwise.
But the best thing, is don't do it in the microwave!

paul perry Melbourne Australia