How do soaps work

1,214 views
834 views

Published on

0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
1,214
On SlideShare
0
From Embeds
0
Number of Embeds
43
Actions
Shares
0
Downloads
34
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

How do soaps work

  1. 1. How Does Soap Work? “ Like dissolves like”
  2. 2. Polar Molecules <ul><li>Some Molecules, such a H 2 O, are POLAR -meaning that they have a (slightly) positive end and a (slightly) negative end like a battery. </li></ul><ul><li>Polarity is the result of unequal sharing of electrons in a bond causing one atom in the bond to be more negative than the other. </li></ul>
  3. 3. Non-Polar Molecules <ul><li>Other Molecules, such as hydrocarbons, or symmetrical molecules (O 2 , N 2 , CO 2 ) are non -polar,meaning that their electrons are shared more or less equally and there is no positive end or negative end. </li></ul>
  4. 4. “ Like dissolves Like” <ul><li>Polar things interact with Polar things, and repel non polar things </li></ul><ul><ul><li>Ex: Water (polar) will dissolve salt (ionic), but will not mix with oil (non polar). </li></ul></ul><ul><li>Non Polar things interact with non Polar things and repel Polar things </li></ul><ul><ul><li>Ex: Kerosene (non polar) will mix with oil (non polar) but not water (polar) </li></ul></ul>
  5. 5. Hydrophilic and Hydrophobic <ul><li>“ Hydro” – water </li></ul><ul><ul><li>“ phobic” – doesn’t like! (non-polar) </li></ul></ul><ul><ul><li>“ philic” – does like (polar) </li></ul></ul><ul><li>Things that interact with polar water molecules are water-loving or hydrophilic. Hydrophilic substances include Salts, alcohols, and anything with polarity. </li></ul><ul><li>Things that don’t like water are water-hating or hydrophobic . Hydrophobic substances are oils, grease, and anything Non polar. </li></ul>
  6. 6. Long chain hydrocarbons <ul><li>Long chain hydrocarbons such as alkanes and alkenes are NON-POLAR Covalent molecules. </li></ul>
  7. 7. Alkanes – non-polar
  8. 8. Alkanes with stuff added on… <ul><li>Adding functional groups such as alcohol (-OH) or Carboxyl (COOH), causes one part of the molecule to become Polar </li></ul><ul><ul><li>The rest of the molecule is still non-polar, especially if it’s a really long chain </li></ul></ul>
  9. 9. Saponification reaction <ul><li>Soap is made by reacting a fatty acid with a base </li></ul><ul><li>This breaks the Carboxyl bonds to form a soap (with a polar end) and Glycerol </li></ul>
  10. 10. Soaps <ul><li>A soap molecule has a Polar hydrophilic ‘head’ and a Non polar hydrophobic ‘tail’ </li></ul><ul><li>The head will interact with the polar water molecules and the tail will interact with the grease molecules. </li></ul><ul><li>This means a soap can interact with both oil and water. </li></ul>
  11. 11. Soaps <ul><li>In this way, the soap molecules can cause grease molecules to dissolve into the water, by forming micelles which allow small particles of grease to be lifted up into the water. </li></ul>
  12. 12. Micelle
  13. 14. Soap dissolves grease <ul><li>The non-polar part of soap dissolves the grease, </li></ul><ul><li>The other end dissolves salts, polar stuff and associates with water </li></ul><ul><li>Voila! Clean dishes! </li></ul>
  14. 15. Words you should understand <ul><li>Polar / polarity </li></ul><ul><li>Non-polar </li></ul><ul><li>Hydrophilic </li></ul><ul><li>Hydrophobic </li></ul><ul><li>Micelle </li></ul>

×