How do I turn room temperature water into boiling water for drinking using an chemical/additive?

Question

I am trying to create instant boiling water using a chemical of sorts, so that it can be consumed by a human. For example; someone could make tea without a kettle or any available water heating systems.

It must be completely safe and if possible, leave no bad tasting remains. Preferably, the chemicals used would have to be easily accessible and stable in its bought state.

I am in high school and just want to do a cool science experiment. I guess this could have endless potential applications. I am also open to other ideas, like making a disposable bottle, that when you twisted the lid, the water would heat up as the chemicals dropped down or the bottle itself heated up. Just any way of doing it would be awesome.

I saw this page but is wasn't consumable ideas:

Can you heat water with additives?

Thanks, Charles

Answer 1

Adding something to water that heats it to 100°C and leaves only water is of course nonsense.

A self-heating cup is easy: You take a double-walled beaker, fill the space between with two compounds that react with great heat but no gas formation, separated by an extra wall with a valve.

Google the self-cooling beer keg. It works very similar, only it gets hot outside, not inside.

Or just google "self-heating coffe cup".

Answer 2

As the comment above suggests, if there was an obvious way to do this it would already be making someone wealthy.

Self heating cans (and gloves) are seen where an exothermic chemical reaction or heat of solution is used to thermally warm food or gloves. The most common application of this method are 'flameless ration heaters' used to heat MRE (military rations).

Typically the ration heater employs an oxidation-reduction reaction e.g. a small amount of water is added to finely powdered magnesium metal, alloyed with a small amount of iron, and table salt. This forms an electrolyte and because the magnesium and iron are in contact it is analogous to many short circuited batteries. The boiling point of water is quickly reached as the reaction proceeds.

Note that the exothermic chemicals are physically isolated from the food being heated. A flameless ration heater might raise the temperature of a 230g meal, 38°C in 10 minutes.