Chemistry C1 6.3 Everyday emulsions.

HideShow resource information
What happens when oils and water are combined?
Oils do not dissolve in water but oils and water can be used to produce emulsions which have special properties.
1 of 15
What are emulsions made from vegetable oils used for?
Many foods.
2 of 15
What are emulsifiers?
Substances that stop oil and water from separating into layers. Most emulsions contain emulsifiers to keep the emulsion stable.
3 of 15
What so the molecules in emulsifiers have?
They have a small part that is hydrophobic and a long part is hydrophilic.
4 of 15
What happens if oil is added to water?
They do not mix and usually separate from each other, forming two layers.
5 of 15
What happens if we shake, stir or beat oil and water together?
Tiny droplets form that can be slow to separate, this type of mixture is called an emulsion.
6 of 15
What do emulsions look like?
They are opaque and thicker than the oil and water they are made from, this improves their texture, appearance and ability to coat and stick to solids.
7 of 15
What emulsions are common within many homes?
Milk, cream, salad dressings and ice cream, also water-based paints and many cosmetic creams are also emulsions.
8 of 15
What is the hydrophilic part of an emulsifier molecule?
The 'head' that is attracted to water.
9 of 15
What is the hydrophobic part of an emulsifier molecule?
The 'tail' that is attracted to oil.
10 of 15
How do emulsifier molecules stop oil and water from separating?
The hydrophobic parts of many emulsifier molecules go into each oil droplet, and so the droplets become surrounded by the hydrophilic parts. This keeps the droplets apart in the water and prevents them joining together and separating out.
11 of 15
Why can't you see through an emulsion?
Because the liquids remain as tiny droplets and do not dissolve. In a solution the substances dissolve which means they mix completely and the solution is clear.
12 of 15
How can you recognise an emulsion?
Opaque; not clear; cannot see through it; thick; coats solids.
13 of 15
What is an emulsifier?
Substance that stops oil and water from separating; with molecules that have a hydrophilic part and a hydrophobic part.
14 of 15
**LOOK UP THE STRUCTURE OF A TYPICAL EMULSIFIER MOLECULE**
*TRY TO DESCRIBE HOW AN EMULSIFIER WORKS USING THE WORDS 'HYDROPHOBIC' AND 'HYDROPHILIC'**
15 of 15

Other cards in this set

Card 2

Front

What are emulsions made from vegetable oils used for?

Back

Many foods.

Card 3

Front

What are emulsifiers?

Back

Preview of the front of card 3

Card 4

Front

What so the molecules in emulsifiers have?

Back

Preview of the front of card 4

Card 5

Front

What happens if oil is added to water?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all Cooking and food additives resources »