Re: Alka Seltzer & warm water?

This sounds like a lot of fun! The water of course starts the Alka Seltzer 
tablet fizzing. It's making carbon dioxide gas, because a weak acid in the 
tablets reacts with the sodium bicarbonate. When the pressure of gas has 
built up enough it shoots the lid off and fires the cannister into the 
air. If you use warmer water it reacts even quicker and the pressure 
builds up quicker and so the thrust is greater.
Hope that explain sit for you.
Kevin