Unit 2: (e) Soaps, detergents and emulsions Flashcards
How are soaps produced?
soaps are produced by the hydrolysis of fats and oils.
What is used to make sodium salts?
alkaline hydrolysis.
What does hydrophobic mean?
Insoluble in water, but soluble in oils and grease.
What does hydrophilic mean?
Insoluble in oils and grease but soluble in water.
What part of soap molecules are hydrophobic?
Tail
What part of soap molecules are hydrophilic?
Head
Explain fully the cleansing action of soaps.
- Soap molecules have an ionic head which is hydrophilic and soluble in water,
- and they have a non-polar covalent tail which is hydrophobic and immiscible in water.
- Agitation separates oil from the surface.
What is formed when soap is added to water?
colloidal suspension
What is colloidal suspension?
soap molecules cluster and form micelles. They remain suspended because like charges repel each other.
What are detergents?
Detergents are a family of compounds that are similar to soaps and work in a similar way.
Why would someone use a detergent over a soap?
Detergents are more useful in areas of hard water.
What is hard water?
Hard water contains dissolved ions and so can form a scum with regular soap.
Why are detergents used in areas of hard water?
Detergents do not react with the ions dissolved in the water and so therefore do not form a precipitate.
Where are detergents derived from?
Crude oil.
What is an emulsion?
2 liquids that are immiscible and the liquids are dispersed throughout each other.
