Superheated water

The water is distilled water that has been microwaved for a few minutes. The white powder added is sugar because it has a pretty big surface area.
Tap water is less likely to have this effect because of the impurities in the water.

Category:

Howto & Style

Tags:

• microwaved
• water

[zackcyboy]

what actually happens is that water has a boiling point of 100 degrees and when you add sugar the boiling point dropes to maybe 70 degrres. The water he had was probably at 90 degrees. When you add the sugar, the boiling point of the solution goes down and as soon as you add it, the water all starts boiling because of the new boiling point which it surpassed when it was pure. Learned this in chemistry

[chreyer]

I also measured the temperature of the water using a digital thermometer as this was for a chemistry project

the measurement wasn't very accurate because once you stick in the thermometer in the water the temperature starts dropping really quickly, but I did achieve some readings that were over 100 degrees.

[zackcyboy]

the boiling point of water changes with the pressure of the enviroment. Where i live the pressure is around 94 kpa in the winter. Water boiles at exactly 100 degress when the pressure is 101 kpa(kilopascals). Getting water to boil at exactly 100 degress is highly unlikely

[chreyer]

You are correct, but what happens here doesn't really involve pressure. When you heat water in a microwave the water is heated uniformly. Once the water reaches the boiling point, and if the water is pure and there are no cracks in the glass, the water won't form bubbles like you see when you boil water in a pot (start of video). Without these bubbles, its hard for the water to transfer heat away and so it just gets hotter. What the sugar does is disturb the water and so bubbles form.

[k0namiman]

Why this happens.

Distilled water contains no impurities. Or, in sciency terms, no nucleation points. There is noplace for bubbles to form in the water. This allows the water to be heated above boiling; boiling water never gets above boiling because the bubbles carry away the energy as fast as you can put it in.

So water here is above 100 celsius. And the sugar is poured in. But it could be anything; what it does is provide a nucleation point. Lots of them. The water now can form bubbles, and >

[k0namiman]

the excess energy is released... all at once. The result is an eruption such as this. And it can happen if the water is microwaved, or heated over a stove. It is a real problem, so chemists dealing with heating distilled water in large volumes usually use what is called a 'boiling stone' which provides a nucleation point.

[torakokoneko]

@chreyer hot lemon tea isn't distilled water, now is it?

[swimmingrules1234]

@zackcyboy no. you're stupid. the water is superheated and has a temperature beyond the boiling point. thermodynamically, the vapor is more stable. kinetically, the liquid needs a path to reach the vapor phase. this means that the water needs a nucleation point so that vapor pockets/bubbles can form. salt provides the nucleation point.

and anyway, the phenomenon is "boiling point elevation/ freezing point depression:" adding sugar *raises* the boiling point

[LVgunbox]

Fail !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!­!!!!

cleaner water, bigger then the boiling temperature

Making the water dirty, of course, that it will begin to boil.

[yamuma8666]

@PKTproductions Are you retarded???



[GapToN]

@zackcyboy actually its not about boiling point its about physical disruption. if you put a stone in it it will have the same effect. Once the super-heated water is disrupted from its stationary state, all the excessive heat makes the water boil instantly. Same reaction happens when you hit the glass with a spoon, grab the glass and thus shaking the water inside (and get your hand burn)

[scrotty11]

it also works with putting in tea or coffee or dirt etc etc

[pandemonic01]

@Jigsaw5435 it's rage has truly hit the boiling point

[Mrcrazydemon115]

Sugar does not act exothermically when added to boiling water. It usually absorbs some of the heat from the water for thermal equilibrium to occur. Enthalpy of solution suggests that when a measured solute is added an endothermic reaction will occur. THE TEMPERATURE OF THE WATER WILL DECREASE.

[tritikar]

@zackcyboy

sorry buddy but adding sugar or salt for that matter too water actually increases the required temperature in order for the water to boil, not the other way around as you suggest.

[Gunner3210]

@zackcyboy Except you were an idiot and didn't pay attention in class. It is not simple stuff. Go back to school.