No special equipment of measuring is required. You can pretty much eyeball the whole process.
Note: This is a bit smelly and can irritate the eyes and skin.
This process is not sufficient to produce "hot ice". Too many contaminants. If you want to get a purified form for use in "hot ice" experiments, there's an Instructable by indigoandblack that should help. It's more involved but much more likely to get the results you want.
Standard Disclaimer: Not liable for damages due to use or misuse. No warranties expressed or implied. For educational purposes only. Safety goggles may be required during use. Void where prohibited. Your mileage may vary. Unauthorized personnel only. Ceci n'est pas une pipe.
Step 1: Materials
- sodium bicarbonate (baking soda)
- acetic acid (vinegar)
- microwavable glass or ceramic containers
- coffee filters
Step 2: Chemical Reaction
Add vinegar very slowly. Too much and the container will overflow with foam. Add a little, wait for the foaming to subside, add a little more.
Keep adding vinegar a little at a time, stirring the mixture.
Stop adding vinegar once the mixture stops bubbling, even with stirring.
What you should have now is a solution of sodium acetate in water. I ended up with the measuring cup nearly full of solution.
Step 3: Boiling
Keep boiling it down until you start to hear sizzling and popping sounds. It should still be a liquid, though. If you end up with a foul-smelling yellow lump, you've gone too far.
The resulting volume should be about 1/10 the original solution.
Note: The container will be very hot.