Soaps Flashcards
How are soaps made?
- Made by boiling animal or vegetable fats with a strong base (usually NaOH)
What do Fats and Oils contain
Contain large multi-ester molecules called triglycerides
What is Soaponification and How does it work?
- The process of creating soaps
- An example of a hydrolysis reaction (reverse of esterfication)
When fats / oils are heated with NaOH the triglycerides break up to form sodium salts and glycerol
Triglyceride + NaOH -> Glycerol + Sodium Salts of Fatty Acids (Salt)
Explain the Action of soaps
- Able to clean because they can bond with both polar and non-polar substances
- Hydrophobic tails embed in the dirt/ grease due to formation of dispersion forces
- Hydrophilic head forms a very strong ion-dipole bond with the water molecules
What are Miscelles?
- When soaps molecules completely surround a dirt particle
What does Dissolving Soap / Detergent in water do?
Lowers the surface tension of the water.
The soap (surfactant) breaks the hydrogen bonding between the molecules and the water spreads out onto the surface rather than remaining in a droplet.
Explain the action of soaps in hard water
- Hard water contains higher levels of calcium and magnesium ions
- These ions bond with the carboxylate ions of soap to form a solid precipitate known as Scum
- Scum reduces the number of soaps ions avaliable to form micelles thus soaps don’t clean
- Detergents don’t form scum
What are the types of Detergents and what are their uses
Detergents are synthetic
Anionic - Negatively charged ion head, used for laundery/dishwashing detergent, good lather and harsh action (heavy duty)
Cationic - Postively charged ion head, used for fabric softeners, hair conditioners, disinfectants - Bond very strongly to negatively chagred surfaces and kills bacteria
Net-ionic: dishwasher detergents / glass cleaners - Low lather formation (little foam buildup in dishwashers)
