Chapter 4: Exploring Diversity of Matter Using Separation Techniques Flashcards
How does the flamingo feed itself?
By putting its head upside down into the water and moving its head from side to side underwater.
What is the use of the flamingo’s large tongue?
As a pump to suck in water containing food particles. The flamingo’s tongue then squeezes out water from its beak.
What happens when water is squeezed out through the flamingo’s beak?
Food particles in the water are trapped by comb-like structures lining the beak.
What does the flamingo depend on to get its food?
The flamingo depends on the separation of food particles from the water to get its food.
What are separation techniques used for?
To separate mixtures.
Name some mixtures that are separated with the use of separation techniques.
- Magnetic and non-magnetic materials
- Liquid and insoluble solid (suspension)
- Liquid and soluble solid (solution)
- Small quantity of substances that are dissolved in a solvent.
What are the different types of separation techniques that I must know?
- Magnetic attraction
- Filtration
- Evaporation
- Distillation
- Paper Chromatography
- Microfiltration
- Reverse Osmosis
How are magnetic and non-magnetic materials separated?
By the use of magnetic attraction, in:
- salvaging of iron and steel
- food processing
How are liquid and insoluble (i.e. cannot be dissolved) solid (suspension) separated?
By filtration, in:
- coffee makers
- water treatment
How are liquid and soluble solid (solution) separated?
By:
- Evaporation, in for instance, salt production;
- Distillation, in for instance, desalination of seawater.
What is the purpose of desalination?
To obtain drinking water.
How are small quantities of substances that are dissolved in a solvent separated?
By paper chromatography, in for instance, finding out the dyes used in ink or food.
What are micro filtration and reverse osmosis used in?
Purification of treated used water.
What is the purpose of purifying treated used water through the use of micro filtration and reverse osmosis?
To obtain drinking water.
What is one of the most popular drinks in the world?
Tea.
How is the traditional tea made?
By mixing dried tea leaves with hot water. The flavour of the tea leaves will dissolve into the water. The mixture of tea leaves and water is then poured over a sieve to separate the tea leaves from the water before the tea is served.
Why is the sieve able to separate the tea leaves from the drink?
Because the tiny holes in the sieve allow the water to pass through, while the tea leaves are trapped.
How is the preparation of tea drinks made simpler nowadays?
Through the use of tea bags.
What is a tea sieve used as?
A simple filter to separate the tea leaves from the tea.
Give some examples of the many mixtures that are around us.
Air, sea water and crude oil.
Can mixtures contain useful substances?
Yes.
How can we make use of the useful substances that are found in mixtures?
By separating these mixtures of substances with the use of physical separation techniques.
Do these physical separation techniques produce any new substances in addition to obtaining the original substances?
No. Chemical reactions are not involved.
Can a combination of two or more techniques be used / needed to separate a mixture sometimes?
Yes.
How many separation techniques must I be familiar with?
5
What is the selection criteria for the separation technique to be use? or
How does one decide on the separation technique to be used?
The technique used to separate a mixture depends on:
- the physical properties of the substances in the mixture; and
- the substances to be obtained from the mixture.
What fact is the use of magnetic attraction based on?
Magnetic attraction makes use of the fact that only some materials are attracted to magnets.
What is magnetic attraction used for?
To separate magnetic materials from non-magnetic materials, e.g. separating a mixture of sand and iron fillings.
What are the advantages / benefits of using magnetic attraction to separate magnetic and non-magnetic materials?
- The separation of magnetic and non-magnetic materials is:
- quicker; and
- more efficient in many industries.
Name some industrial applications of magnetic attraction.
- Salvaging of iron and steel
2. Food processing
Are iron and steel magnetic materials?
Yes
Where can iron and steel be recovered from?
Junkyards
Why are iron and steel recovered from the junkyard?
So that these metals can be recycled.
What is the advantage / benefit of recycling iron?
Recycling iron prevents iron from being used up as metals are limited natural resources, i.e. prevents the depletion of natural resources.
How are iron and steel separated from other materials in the junkyard?
Through the use of a powerful magnet. When the magnet is turned off, iron and shell are dropped into a collection bin.
What happens to the iron and steel that are retrieved from the junkyard by the powerful magnet?
The iron and steel are sold as scrap metal and brought to recycling centres.
What happens to these recycled iron and steel?
They are reused in new objects that are made.