View Full Version : How does soap work?

04-10-2000, 03:46 PM
How does soap work? I know its some sort of chemical reaction...

04-10-2000, 03:52 PM
Originally posted by sethdallob:
How does soap work? I know its some sort of chemical reaction...

Here I go, thinking back to Junior High School...

A chemical in soap (usually found in Sodium Lauryl (or lauryth) sulfate) breaks down the bonds between dirt molecules. Or, more precisely, between all molecules. Then the stuff can be rinsed off.

Or, using someone else's bigger words:
Like modern soapless detergents (usually sulfonated alcohols), soaps cleanse by lowering the surface tension of water, by emulsifying grease, and by absorbing dirt into the foam.

For more info, check out http://www.ask.com/main/FinalAnswer.asp?qCategory=REF%5F&Link=http%3A%2F%2Faj%2Eencyclopedia%2Ecom%2Farticles%2F12027%2Ehtml&Title=Encyclopedia%2Ecom&Answers=1&ajparam_list1=2 9&ajparam_fillers=%7C29%5B5458%5D%7C&ajparam_qid=5560&site_name=Jeeves&scope=web&ask=Where+can+I+find+a+concise+encyclopedia+article+on+soap%3F&origin=0&metasearch=yes

: :cool::

04-10-2000, 03:55 PM
Cecil has addressed this: http://www.straightdope.com/classics/a2_398.html

04-10-2000, 03:55 PM
Sorry! :0

Here is that link...

04-10-2000, 03:56 PM
I can't help it...

You can make some neato soap.

Take some 18 molar NaOH (sodium hydroxide) and just 'spill it' on your skin. Start rubbing....

You'll get the neatest lather. Basically, it sort of reacts with the lipids in your skin. It'll foam up. It leaves a nasty basic burn though. So don't do it on purpose.

"polar disolves polar" and "non-polar disolves non-polar" So in effect, water being polar, can't really disolve non polar stuff like oils, and grease. Thats why you use the non-polar soaps :) Take a couple chemistry courses in college, and you think you're all smart....

I guess I'm too big for my britches.

I hope this helped a little


04-13-2000, 09:58 PM
Actually, soap molecules are polar on one end and nonpolar on the other, allowing them to mix with polar water and nonpolar dirt. Kind of like an adapter.

04-14-2000, 02:47 AM
did i say that it wasn't polar? I'm sure some soaps are polar, However, most things soap disolves are non-polar, thus soap being non-polar to disolve it.

I'm sure there are some soap molecules, if there is such a thing have portions that aren't non-polar. If they're big enough.

Anyway, did you try the NaOH? muhaha

04-14-2000, 11:34 AM
OP: How does soap work?

Get a bar of it wet. Get your body wet too. Rub wet soap all over your body. Put bar of soap down. Rinse.

Do this once a day (once a week in Europe). Localize to hands after using a toilet.

Wrong thinking is punished, right thinking is just as swiftly rewarded. You'll find it an effective combination.

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