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Thread: How does soap work?

  1. #1 How does soap work? 
    ...matter and pixie dust wegs's Avatar
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    I had no idea that soap is a fatty acid of salt? What?

    https://www.thoughtco.com/how-dos-soap-clean-606146


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  3. #2  
    Bullshit Intolerant PhDemon's Avatar
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    OK, the molecules of soap contain a hydrophilic (water loving) bit and a hydrophobic (water hating bit). The fatty acid is the hydrophobic bit. What happens is the hydrophobic bit clings on to any grease or oil on the thing you are washing, when rinsing with water the soap/grease forms little globules (micelles) with the grease and hydrophobic bit of the soap on the inside and the hydrophilic bit on the outside. These will no longer stick to you or your clothes and can be rinsed off.

    Ah misread your post and thought you were asking how soap works... If you'd seen the film Fight Club you would have known soap was made from fatty acids, that's why they raid the liposuction clinic!

    Also soap is not a fatty acid of salt, but the salt of a fatty acid. These may sound the same but are very different to a chemist!


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  4. #3  
    exchemist
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    Quote Originally Posted by wegs View Post
    I had no idea that soap is a fatty acid of salt? What?

    https://www.thoughtco.com/how-dos-soap-clean-606146
    Fats are mainly esters of fatty acids, bonded to an alcohol called glycerol (="glycerine"). Saponification of a fat breaks these bonds , liberating the fatty acids (and the gylcerol but this is not important to what follows).

    However as strong alkalis, such as sodium or potassium hydroxide are used to break the bonds, the fatty acids get neutralised in the process, so you end up with a fatty acid salt, e.g. sodium or potassium stearate, rather than stearic acid.

    The acid salt end of the molecule has a chemical group - COO⁻ on it, which is polar and can form hydrogen bonds with water. So that end is attracted to water (hydrophilic). The other end is just a hydrocarbon chain, which is repelled by water (hydrophobic) but is attracted to oils and grease. Hence its detergent action, as PhDemon has explained.

    There are many other classes of synthetic detergents, used for laundry, dishwashing etc, using a wide variety of chemistry, but all share the essential feature of molecules with a hydrophilic part and a hydrophobic part.
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  5. #4  
    ...matter and pixie dust wegs's Avatar
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    Saw your post on the other forum, exchemist - thank you! And thanks as well, PhDemon.

    i don't know why, but this changes my view of soap. lol This is something that I wish I didn't know. I'm going to be thinking about this process during my next shower. :/
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  6. #5  
    Samurai of Logic Falconer360's Avatar
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    Quote Originally Posted by wegs View Post
    Saw your post on the other forum, exchemist - thank you! And thanks as well, PhDemon.

    i don't know why, but this changes my view of soap. lol This is something that I wish I didn't know. I'm going to be thinking about this process during my next shower. :/
    Kind of like how a person should never learn the process for making hot dogs if they still wish to eat them. lol
    "For every moment of triumph, for every instance of beauty, many souls must be trampled." Hunter S Thompson

    "It is easy to kill someone with a slash of a sword. It is hard to be impossible for others to cut down"
    - Yagyu Munenori

    "Only a warrior chooses pacifism; others are condemned to it."
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  7. #6  
    ...matter and pixie dust wegs's Avatar
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    Quote Originally Posted by Falconer360 View Post
    Quote Originally Posted by wegs View Post
    Saw your post on the other forum, exchemist - thank you! And thanks as well, PhDemon.

    i don't know why, but this changes my view of soap. lol This is something that I wish I didn't know. I'm going to be thinking about this process during my next shower. :/
    Kind of like how a person should never learn the process for making hot dogs if they still wish to eat them. lol
    omg, yes! As a matter of fact, I watched a youtube video recently on that very thing, out of morbid curiosity, and wish I hadn't. Never really liked hot dogs, but I'd eat the occasional one at a bbq now and then. No more!

    I've done research on factory farming as well, and it's so disgusting how some of our food is sourced and processed.
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  8. #7  
    Samurai of Logic Falconer360's Avatar
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    Quote Originally Posted by wegs View Post
    omg, yes! As a matter of fact, I watched a youtube video recently on that very thing, out of morbid curiosity, and wish I hadn't. Never really liked hot dogs, but I'd eat the occasional one at a bbq now and then. No more!

    I've done research on factory farming as well, and it's so disgusting how some of our food is sourced and processed.
    I refuse to watch any videos on the making of hot dogs. I know they're made of grossness, but I can still enjoy the occasional one at BBQs now and then. As it is my dad ruined fish sticks for me as a kid, because he worked in the fish industry up in Alaska in the eighties, so he talked about how gross they were and the parts of fish that ended up in them.

    Factory farming is so gross, but I just try not to think of it as I eat my chicken caesar wrap lol.
    "For every moment of triumph, for every instance of beauty, many souls must be trampled." Hunter S Thompson

    "It is easy to kill someone with a slash of a sword. It is hard to be impossible for others to cut down"
    - Yagyu Munenori

    "Only a warrior chooses pacifism; others are condemned to it."
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  9. #8  
    ...matter and pixie dust wegs's Avatar
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    Quote Originally Posted by Falconer360 View Post
    Quote Originally Posted by wegs View Post
    omg, yes! As a matter of fact, I watched a youtube video recently on that very thing, out of morbid curiosity, and wish I hadn't. Never really liked hot dogs, but I'd eat the occasional one at a bbq now and then. No more!

    I've done research on factory farming as well, and it's so disgusting how some of our food is sourced and processed.
    I refuse to watch any videos on the making of hot dogs. I know they're made of grossness, but I can still enjoy the occasional one at BBQs now and then. As it is my dad ruined fish sticks for me as a kid, because he worked in the fish industry up in Alaska in the eighties, so he talked about how gross they were and the parts of fish that ended up in them.

    Factory farming is so gross, but I just try not to think of it as I eat my chicken caesar wrap lol.
    ew, fish sticks. lol Just the idea of fish being molded into sticks is disturbing.

    Now I'll have soap to add to my list of things I don't want to think about!

    I'm assuming liquid body washes/soaps are made the same way. Sigh.
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  10. #9  
    exchemist
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    Quote Originally Posted by wegs View Post
    Saw your post on the other forum, exchemist - thank you! And thanks as well, PhDemon.

    i don't know why, but this changes my view of soap. lol This is something that I wish I didn't know. I'm going to be thinking about this process during my next shower. :/
    I don't understand why it bothers you. soap-making is an ancient chemical process, used by the Gauls and Germanic tribes in the time of ancient Rome, who mixed alkaline ashes ("potassium" comes from "pot ash") with fats to make a substance for cleaning the skin and hair - and wool too, apparently. It is made from fats but it is not a fat, because the fat has been split into into its component parts.
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  11. #10  
    ...matter and pixie dust wegs's Avatar
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    Quote Originally Posted by exchemist View Post
    Quote Originally Posted by wegs View Post
    Saw your post on the other forum, exchemist - thank you! And thanks as well, PhDemon.

    i don't know why, but this changes my view of soap. lol This is something that I wish I didn't know. I'm going to be thinking about this process during my next shower. :/
    I don't understand why it bothers you. soap-making is an ancient chemical process, used by the Gauls and Germanic tribes in the time of ancient Rome, who mixed alkaline ashes ("potassium" comes from "pot ash") with fats to make a substance for cleaning the skin and hair - and wool too, apparently. It is made from fats but it is not a fat, because the fat has been split into into its component parts.
    I don't know why, really.
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  12. #11  
    exchemist
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    Quote Originally Posted by wegs View Post
    Quote Originally Posted by exchemist View Post
    Quote Originally Posted by wegs View Post
    Saw your post on the other forum, exchemist - thank you! And thanks as well, PhDemon.

    i don't know why, but this changes my view of soap. lol This is something that I wish I didn't know. I'm going to be thinking about this process during my next shower. :/
    I don't understand why it bothers you. soap-making is an ancient chemical process, used by the Gauls and Germanic tribes in the time of ancient Rome, who mixed alkaline ashes ("potassium" comes from "pot ash") with fats to make a substance for cleaning the skin and hair - and wool too, apparently. It is made from fats but it is not a fat, because the fat has been split into into its component parts.
    I don't know why, really.
    If it makes you feel better, it does not have to involve animal fats. You can make soap from vegetable fats too. They are also triglyceride esters, just of different fatty acids, things such as oleic acid.https://en.wikipedia.org/wiki/Vegan_soap
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  13. #12  
    ...matter and pixie dust wegs's Avatar
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    Quote Originally Posted by exchemist View Post
    Quote Originally Posted by wegs View Post
    Quote Originally Posted by exchemist View Post
    Quote Originally Posted by wegs View Post
    Saw your post on the other forum, exchemist - thank you! And thanks as well, PhDemon.

    i don't know why, but this changes my view of soap. lol This is something that I wish I didn't know. I'm going to be thinking about this process during my next shower. :/
    I don't understand why it bothers you. soap-making is an ancient chemical process, used by the Gauls and Germanic tribes in the time of ancient Rome, who mixed alkaline ashes ("potassium" comes from "pot ash") with fats to make a substance for cleaning the skin and hair - and wool too, apparently. It is made from fats but it is not a fat, because the fat has been split into into its component parts.
    I don't know why, really.
    If it makes you feel better, it does not have to involve animal fats. You can make soap from vegetable fats too. They are also triglyceride esters, just of different fatty acids, things such as oleic acid.https://en.wikipedia.org/wiki/Vegan_soap
    I couldn't pinpoint it, but that's it! That's what makes me cringe, the potential animal cruelty of it all. And my ignorance isn't an excuse. Thanks for posting this
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  14. #13  
    Forum Professor mmatt9876's Avatar
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    Quote Originally Posted by PhDemon View Post
    OK, the molecules of soap contain a hydrophilic (water loving) bit and a hydrophobic (water hating bit). The fatty acid is the hydrophobic bit. What happens is the hydrophobic bit clings on to any grease or oil on the thing you are washing, when rinsing with water the soap/grease forms little globules (micelles) with the grease and hydrophobic bit of the soap on the inside and the hydrophilic bit on the outside. These will no longer stick to you or your clothes and can be rinsed off.

    Ah misread your post and thought you were asking how soap works... If you'd seen the film Fight Club you would have known soap was made from fatty acids, that's why they raid the liposuction clinic!

    Also soap is not a fatty acid of salt, but the salt of a fatty acid. These may sound the same but are very different to a chemist!
    So soap molecules for little bubbles, if you will, around grease and dirt and are washed away from your body or a surface with water.
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    hi
    you are talking about how soap work.
    There are many other classes of synthetic detergents, used for laundry, dishwashing etc, using a wide variety of chemistry, but all share the essential feature of molecules with a hydrophilic part and a hydrophobic part.for more knowledge you can google on it.
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  16. #15  
    exchemist
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    Quote Originally Posted by bestwork1989 View Post
    hi
    you are talking about how soap work.
    There are many other classes of synthetic detergents, used for laundry, dishwashing etc, using a wide variety of chemistry, but all share the essential feature of molecules with a hydrophilic part and a hydrophobic part.for more knowledge you can google on it.
    Fuck off, you miserable plagiarist* (and probable robot).

    *See post 3
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  17. #16  
    Forum Radioactive Isotope
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    Quote Originally Posted by exchemist View Post
    Quote Originally Posted by bestwork1989 View Post
    hi
    you are talking about how soap work.
    There are many other classes of synthetic detergents, used for laundry, dishwashing etc, using a wide variety of chemistry, but all share the essential feature of molecules with a hydrophilic part and a hydrophobic part.for more knowledge you can google on it.
    Fuck off, you miserable plagiarist* (and probable robot).


    *See post 3
    Didn't see that (even though I did report the post at the time as probable spam -or some sort of questionable)

    There were very similar posts on other forums by the same username.
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  18. #17  
    exchemist
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    Quote Originally Posted by geordief View Post
    Quote Originally Posted by exchemist View Post
    Quote Originally Posted by bestwork1989 View Post
    hi
    you are talking about how soap work.
    There are many other classes of synthetic detergents, used for laundry, dishwashing etc, using a wide variety of chemistry, but all share the essential feature of molecules with a hydrophilic part and a hydrophobic part.for more knowledge you can google on it.
    Fuck off, you miserable plagiarist* (and probable robot).


    *See post 3
    Didn't see that (even though I did report the post at the time as probable spam -or some sort of questionable)

    There were very similar posts on other forums by the same username.
    That's interesting. I'll have a look.
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  19. #18  
    ...matter and pixie dust wegs's Avatar
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    Quote Originally Posted by exchemist View Post
    Quote Originally Posted by bestwork1989 View Post
    hi
    you are talking about how soap work.
    There are many other classes of synthetic detergents, used for laundry, dishwashing etc, using a wide variety of chemistry, but all share the essential feature of molecules with a hydrophilic part and a hydrophobic part.for more knowledge you can google on it.
    Fuck off, you miserable plagiarist* (and probable robot).

    *See post 3
    It's nice to see this forum is alive and...um...well. lol
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  20. #19  
    exchemist
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    Quote Originally Posted by wegs View Post
    Quote Originally Posted by exchemist View Post
    Quote Originally Posted by bestwork1989 View Post
    hi
    you are talking about how soap work.
    There are many other classes of synthetic detergents, used for laundry, dishwashing etc, using a wide variety of chemistry, but all share the essential feature of molecules with a hydrophilic part and a hydrophobic part.for more knowledge you can google on it.
    Fuck off, you miserable plagiarist* (and probable robot).

    *See post 3
    It's nice to see this forum is alive and...um...well. lol
    Hello wegs, nice to see you here.

    But really, to have some bot quote my own words back as if they were a new contribution is bloody irritating.
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