# Is there a liquid that looks like water but boils at a low temperature? [closed]

I just watched a movie where someone put their hand into boiling water. Disregarding how this was actually done, I wondered whether there was a liquid which could be used for an illusion of someone "putting their hand into boiling water".

For this it would have to look like water, boil at a comfortable temperature (< 50 degree celsius) and should not be so toxic that you can't put your hand into it. Smell doesn't matter.

Is there some liquid that fulfils these requirements?

• Diethyl ether (you don't want to use this one due to its extreme flammability, which you didn't mention as a requirement, but which is important too), and then probably some freones. – Ivan Neretin Nov 23 '16 at 14:46
• Maybe one of the refrigerants? Generally non-toxic and non-flammable. CFC-113a (1,1,1-trichloro-2,2,2-trifluoroethane) boils at 46 $^{\circ}$C, for example. – Todd Minehardt Nov 23 '16 at 14:47
• @ToddMinehardt Most environmental regulatory agencies would probably be terrifically upset at someone playing around with an open container of a CFC. – hBy2Py Nov 23 '16 at 15:05
• Movies don’t usually strain for realism: many “boiling water” scenes look like they were cold water + dry ice. This creates bubbling and something like steam but involves no risk to health. – matt_black Nov 23 '16 at 16:01
• @matt_black or pumping air into the bottom of a container of cold water (fish tank components) – Chris H Nov 23 '16 at 16:24

## 3 Answers

The following list gives some boiling points

I've added the suggestions of Ben Norris and Todd Minehardt.

1. Common organic solvents

Please read the Material Safety Data Sheets (MSDS), pay attention to the hazard statements and decide whether you (still) want to put your bare hands into these solvents!

1. Refrigerants

• @Klaus - You might want to add some refrigerants to your list, since they have low- to non-toxicity ratings and are also not nearly as hazardous in terms of flammability as the items you list. Look at trichlorofluoromethane, for example, which boils at 24 $^{\circ}$C. And there are several others in the right temperature range. Just a suggestion. – Todd Minehardt Nov 23 '16 at 14:56
• @ToddMinehardt Thanks a lot for the suggestion! I've added some of the refrigerants. – Klaus-Dieter Warzecha Nov 23 '16 at 15:54
• Liquid nitrogen: 77 K. Obviously, the other end is bad too, but I've definitely stuck my hand in and out real fast without any problems. – Zhe Nov 23 '16 at 15:58
• @Zhe Dimethyl zinc has a bp of 46°C, but I haven't added that either - for reasons ;-) – Klaus-Dieter Warzecha Nov 23 '16 at 16:06

Most of the solvents mentioned in the other answers don’t actually look that much like water. They have a lower surface tension, i.e. they make flatter but larger drops on a surface if a given volume is spilt. They also have very different ripple characteristics. To exemplify the difference: if you usually drink (and see) whole milk and then suddenly experience fat free milk, it will look a lot more like white water than actual milk.

On the other hand, dichloromethane has a higher surface tension, makes smaller spills and in some ways behaves a lot more like water in beakers (while still being different, unfortunately). It is much less flammable than ether and similar solvents, so heating it is safer. And it boils at a mere $40~\mathrm{^\circ C}$. Or, as somebody once put it in a synthesis problem seminar:

Ah, refluxing dichloromethane; i.e. room temperature.

You wouldn’t want to put your bare hands in forever, but boiling DCM should be much better for this purpose than boiling water.

Also, consult the material safety data sheet and be certain you know what you’re doing before you attempt this!

The liquids suggested so far are either flammable solvents, or CFC refrigerants (bad for the ozone layer and tightly controlled.)

I can tell you from experience that a measuring cylinder of butane boils with an appearance like water but is pretty cold (around 0 C) so I dont recommend putting your hand in it (liquid nitrogen actually feels less cold.) Whatever you do, with flammable solvents, do it outside and away from flames!

Solid carbon dioxide "dry ice" in water is a better option. there are many videos on Youtube, for example this one which illustrates the effect. It also shows one of the problems: the fog goes down, rather than up, due to CO2 being denser than air. If you want the fog to rise this will also be a problem with other materials. A fun thing is to add some indicator to the water, whose colour is affected by the acidity of the CO2 dissolved in the water.

The fog is largely water condensed by the CO2 (as the vapour is produced at the sublimation temperature of CO2, -78C.) If you want vigorous effevescence without so much fog, you could look into the reaction of acids with carbonates and bicarbonates. If you mix solutions, you will find the reaction instantaneous and the material will bubble so fiercely it jumps out of the pot. Solid carbonates react much more slowly, and you can fine tune it with both the acid strength and the particle size. Here is an example.

EDIT: Another reaction that produces a harmless gas is the catalytic decomposition of hydrogen peroxide solution to water and oxygen. You can fine tune the speed of reaction very easily by varying the amount of catalyst. you can see this both with and without the optional dishwashing liquid here (turn the music down if you don't like it!) and there are far more dramatic demonstrations on Youtube. It should be borne in mind that the more dramatic demonstrations this do generate a lot of genuine heat though.

If you want smoke, commercial smoke machines often use propylene glycol (which has a higher boiling point than water) and is much less toxic than ethylene glycol (as it is metabolized to lactic rather than oxalic acid.)