Separation. Flashcards
What is a mixture?
A substance made up of 2 or more substances physically put together e.g. water + salt and sand + water.
Define filtration.
Filtration is a process that is used to separate liquids from insoluble substances.
Where is filtration mainly used?
Filtration is mainly used in the large-scale treatment of water in towns and cities.
For Figure 7.1.1 page 96, explain how the suspensions and dirt will be removed?
The combination of rocks, coarse sand, charcoal, and fine sand acts as a filter paper and will remove all suspension and dirt from the water.
However, this water is not safe to drink.
Water intended for human consumption should be safe, meaning what exactly?
Water intended for human consumption should be safe, meaning it should be free from pathogens and harmful chemical substances.
The major steps in a typical water purification system comprise one or more of the following measures:?
The major steps in a typical water purification system comprise one or more of the following measures:
- Storage.
- Filtration.
- Disinfection.
The major steps in water treatment are:?
- Sedimentation.
- Filtration.
- Disinfection.
Describe sedimentation.
Heavy particles settle at the bottom of the tank.
Describe filtration.
Water flows through sand and charcoal to remove insoluble particles.
Describe disinfection.
Chlorine is bubbled through water to kill pathogens.
What are pathogens?
Pathogens are tiny living organisms, such as bacteria or viruses, which cause disease.
Four separation methods are?
Four separation methods are evaporation, filtration, winnowing, and magnetism.
Describe winnowing.
Winnowing is a technique used to separate substances of different densities.
Name two applications of winnowing.
- Separate husks from seeds.
- Separate groundnuts and shells.
What is chlorination?
Chlorination is the process of adding chlorine to drinking water to kill parasites, bacteria, and viruses.
Why do we use winnowing to separate the seeds from the husks?
We use winnowing to separate the seeds from the husks because the seeds have higher densities than the husks.
Describe magnetism.
We can use a magnet to separate non-magnetic materials from magnetic materials.
Why do grinding mills use magnets?
Grinding mills use magnets to protect their sieves from metallic objects.
Name three applications of magnetism.
- Grinding mills use magnets to protect their sieves from iron objects.
- Scrapyards.
- Mining industry.
Name two applications of evaporation.
- Sugar production.
- Production of ammonia nitrate fertilizer.
Name one application of filtration.
- Water treatment plant.
How is water distilled?
Water is distilled through evaporation and condensation.
What is produced during distillation?
Pure alcohol.
Where else does distillation take place?
Distillation happens naturally during the water cycle.
