Chemistry of Soap

Getting Down and Dirty

Differences in Electronegativity

• If the difference in electronegativity is ___________ between two elements in a bond then an ____________ bond is formed. If the difference is _________________ ______________ then the bond formed is __________________. This difference in electronegativity also generates _______________in the molecule or compound. The more electronegative end has a partial ___________________ charge and the other end is slightly more ____________________.

A Bit of Polarity = A Cleaner Tomorrow

• _____________________ is what is responsible for the chemical qualities of soap.

• The strength of the bond __________________ as the electronegativity difference _____________________.

• Soap is formed by combining ________________ with ____________________________ (lye or caustic soda).

• When the chemical reaction is complete, _________ and ______________are the products. One end of the soap is sticky or ______________-. This is also called __________________. The other end is ___________or water-hating. Another word for this is _______________. The sticky end is attracted to __________________ while the non-sticky end is attracted to _______________________ ends.

What is Soap Made Of?

• Soaps are made of molecules that are both ________ and ______________. The molecule has a long _________________ tail that allows it to dissolve grease, and a _________________ that is water soluble.

Soap!

• A soap molecule. The grey, red, and white spheres represent ______________, _____________, and _______________ atoms, respectively. The sodium ion near the negatively charged oxygen atoms is ______________________-.

• The head is the sodium or potassium salt of an ______________________.

• How do you make a soap molecule? _____________________ contains them, chemically bound to a small three-armed molecule called _______________. The links between each of the _____________ molecules and the _______________ are easily broken in a ___________________ solution:

Animal Fat ‘glycerol’

• This reaction was used to make ________ by treating animal fat with _____________ (which contain a high concentration of _________________________________) long before the chemistry of the process was understood.

+ 3 NaOH +

3 RCOO- Na+

Now, write the Formation of Soap in YOUR OWN words from fat and

NaOH!