Naked Science Forum

Non Life Sciences => Chemistry => Topic started by: neilep on 24/07/2007 20:02:34

Title: How Hot Does Water Need To be To Scald ?
Post by: neilep on 24/07/2007 20:02:34

We all know that water boils at 100C......but what temperature does the skin damaging factors appear ?.........80 ?..70 ?

The answer may lead to a further question...especially if it's below 70c

Do different colour skins have different resistences ?

Title: How Hot Does Water Need To be To Scald ?
Post by: Bored chemist on 24/07/2007 20:36:32

How long do you leave the skin in the water?

Title: How Hot Does Water Need To be To Scald ?
Post by: eric l on 24/07/2007 20:39:20

One minute at 60°C does hurt a lot but not harm if you put your hand immediately in cold water after that (from experience, and the minute may have been a little less than 60 seconds)

Title: How Hot Does Water Need To be To Scald ?
Post by: neilep on 24/07/2007 20:47:27

Thanks YOU BC and Eric !..I had not considered the fact the time factor of actually the length of contact !



THANK YOU also as you have kind of answered my supplemental question...in that I understand that the alcohol in wine (when used in cooking)  catches light at about 70c...so I was going to ask if such a flame would hurt the skin !!......which I gather is now ' yes '.

Do you know of a flame that has a very low temeprature ?...ie: low enough to put your finger in causing no harm and not much discomfort ?

Title: How Hot Does Water Need To be To Scald ?
Post by: another_someone on 24/07/2007 21:04:28

I am not aware that alcohol catches file when cooking - but it does boil off.

You can actually pour alcohol over your hand, and set light to it, and it will not burn your hand.  It is not just the temperature, but because of the low density, it actually does not contain much energy - and in any case, since the heat rises, and your hand is beneath the flame, that too helps to protect your hand.

On the other hand, in different contexts, ethanol has been used as rocket fuel, and the temperatures and energy there are considerably hight that the temperature over your Christmas pudding.

Title: How Hot Does Water Need To be To Scald ?
Post by: neilep on 24/07/2007 21:22:25

Thank You George....I did not mean for it to sound as if the wine spontaneous combusts at 70c but that the alcohol reaches it's flammable temperature at 70c.

That's very interesting about the hand alcohol thing !..If I had some I would try it..but I am tea-totaller !


Wow !!..Christmas pudding as rocket fuel !!..this must be how Santa gets about so quickly !!