Soap Flashcards
What are soaps made up of by
Reacting Fatty acids from a fat or an oil with sodium or potassium hyroxide form the sodium or potassium salts
These salts produces are
Soap
Soap is made by heating fats or oils with an
Alkali
What is this sort of reaction called
Alkaline hydrolysis or saponification
The production of soap is made up of two parts
•Hydrolysis of fat or oil to form fatty acids
• Neutralise of the fatty acid with sodium or potassium hydroxide to form the sodium or potassium salt
The alkali used will also catalyse the
Hydrolysis process
Both reactions take place in the one reaction vessel where all
The substance are boiled up together
A soap has 2 parts
• A long covalent part known as the tail
• an ionic part known as the head
Hydrophilic and hyrophobic
Hydrophollic - will dissolve in water and other polar substances (polar£
Hydrophobic - will not dissolve in non polar substance (non polar)
Soaps work depending on
•their structure and the bonding of their negative ions
Soap ions have the
Head and tail
The hydrophilic head is what
Polar part of the substance that contains the charged ion which means it’s ionic and soluble in water
The hydrophobic tail is non polar, organic chain which is
Insoluble in water but soluble in other non polar compounds like oil or greese
Cleansing of soaps
The negatively- charged ball like structure repel each other and the oil or grease is
Kept suspended in water
When you rinse the suspended micelles
Are washed away with the water
Hard water meaning
Used to describe water containing high levels of dissolved metal ions such as calcium & magnesium
When soap is used in hard water it can form an insoluble precipitate called
Scum
The scum that forms reduced the
Effectiveness of the soap to clean
Detergents are what
Substances with non polar hyrophobic tails and ionic hydrophilic heads very similar to soaps
The hydrophobic tail and hydrophilic heads very similar mean that detergents have
Identical cleaning actions to soaps
What does this do
Remove oil and grease like soap
But scum isn’t formed with detergents with hard water it can
Advantages of detergents
•Their use in areas with hard water containing high
Both soaps and detergents added to hard water will produce
Calcium and magnesium salts
These ions will react with soap ions to form scum as the calcium and magnesium salts that are
Insoluble in water
The calcium and magnesium salts formed with detergent ions are
Soluble in water so no scum is fomredb
What are detergents found In
Washing powder
Carpet cleaners
Shampoo
Emulsion is formed when two immiscible liquids are added together and
shaken vigorously
An emulsion is therefor a mixture and not a
Solution and consist of one liquid dispersed in the other
If some emulsions are left to stand they will
Separate into two separate layers. Eg vegetable oil
To prevent this from happening substances called emulsifiers are added
Emuliifiers are what
Compounds similar to soaps and detergents ions in that they have hydrophobic tails and hydrophollic heads very similar
An emulsifier can be used to prevent
Non polar and polar liquids separating two layers
Common use of emulsifiers
• monoglycerides
•Diglycerides
Emulsifiers for use in food can be made by reacting edible oils with glycerol
In molecules formed, only one or two fatty acids groups are linked to
Each glycerol backbone
The hydroxy groups present in the emulsifier are hydrophilic
Whilst the fatty acid chains are hydrophobic
The polar RH groups of the compound or hydrophilic heads of the emulsifier
And these make it soluble in water
The teas are made up of nonpolar fatty acid chains which are hydrophobic and therefore
Soluble and nonpolar substances
In this way, that emulsifier acts like a soap or detergent
The hydrophobic fatty acid chain dissolves in oil whilst the hydrophilic hydroxide dissolves in water forming a stable emulsion
Examples of emulsions
Ice cream
Processed meats
Mayonnaise
