Soaps, detergents and emulsions

How are soaps produced?

by the alkaline hydrolysis of edible fats and edible oils

hydrolysis of edible fats and edible oils produces what?

three fatty acid molecules and one glycerol molecule

the fatty acid molecules are ________ by the alkali, forming what?

• neutralised

• water-soluble ionic salts called soaps

How can soaps be used?

remove non-polar substances such as oil and grease

Soap ions have? (And solubility)

• Long non polar tails that are readily soluble in non-polar compounds

• Ionic head that are water soluble

What part of the soap ion is hydrophobic and which part is hydrophilic

• Hydrophobic - Long non polar tail

• Hydrophilic - Ionic heads

The hydrophobic tails dissolve in what?

Oil or Grease

The hydrophilic head remains in what?

The surrounding of water

__________ causes ball-like structures to form.

Agitation

The negatively-charged ball-like structures do what?

repel each other and the oil or grease is kept suspended in the water

What is hard water?

water containing high levels of dissolved metal ions

What is formed when soap is used in hard water?

Scum, an insoluble precipitate

What are soapless detergents?

substances with non-polar hydrophobic tails and ionic hydrophilic heads

What do soapless detergents remove?

oil and grease in the same way as soap

Soapless detergents do not form what?

Scum with hard water

What can an emulsifier be used for?

to prevent non-polar and polar liquids separating into layers

What does an emulsion contain?

small droplets of one liquid dispersed in another liquid

How can emulsifiers used in food be made?

by reacting edible oils with glycerol

When the emulsifiers for use in food are formed only what is linked?

only one or two fatty acid groups are linked to each glycerol backbone

In the emulsifiers what is hydrophobic and what is hydrophilic?

The hydroxyl groups present in the emulsifier are hydrophilic whilst the fatty acid chains are hydrophobic

The hydrophobic fatty acid chains dissolve in ____ whilst the hydrophilic hydroxyl groups dissolve in ____ , forming what?

• Oil

• Water

• a stable emulsion