Water Flashcards

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What is the meaning of the term Solute?
A bonded substance
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Which 2 solutes are dissolved in water?
Hydrogen and Oxygen
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Guve examples of the ions that dissolve in water as it runs over or through the ground.
Sodium, Calcium, Magnesium, Sulfate, Hydrogen, Carbonate, Chloride
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Name 2 of the most important gases dissolved in water.
Oxygen and Carbon Dioxide
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Why is it inadvisable to drink untreated water from lakes and rivers?
1) Pollutants 2) Micro-organisms
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How do pollutants enter water?
Rainfall, being washed down through fields ect.
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List ways we can reduce water consumption.
1. Takie shorter showers 2. Re-use bath or sink water for watering plants 3. Having toilets with a setting to allow for shorter flushes 4. Insulating water pipes to reduce the chances of bursting in the winter 5. Having a water meter
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Describe the term abstracting water.
Extracting water for human use
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Why might some methods be opposed by local populations?
Enviromental impact
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Why can distributing water be expensive?
Due to the fact that that areas far away have to have water piped to them.
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What are the goals of the United Nations Millenium Development?
To get clean drinking water to 88.5% of the worlds population.
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What is water purification?
This is the process where water obtained from rivers, lakes and underground wellas are piped off to a water treatment plant to be cleaned in order for us to drink it safley.
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What is the process of water purification?
1)Sedimentation 2)filtration 3)chlorination
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What happens during sedimentation?
This is where all solid impurities (e.g. twigs, leaves, grass) settle at the bottom of a tank the water is stored in.
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What happens during filtration?
This is where all the smaller impurities are filtered out.
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What happens during chlorinaton?
This is where chlorine is added to the water to kill all remqaining bacteria.
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What do filter beds and sedimentation tanks remove from dirty water?
They remove solid objects from the water such as vegetation.
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Why is tap water clean but not pure?
Due to the fact that minerals remain in the water.
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Why are small amounts ofnfluoride added to drinking water?
Helps keep the mouth healthy and prevents tooth decay.
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Describe the term demineralisation.
Acids cause calcium and phosphates (of which the enamel is formed) to dissolve.
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Describe the term remineralisation.
The saliva eventually neutralises the the acid and minerals re-enter the enamel.
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3 benefits of adding fluoride to water.
1) Fluoride alters the structure of enamel so it is more resistant to acid attack, this is more important tpo young children. 2) Low levels of fluoride encourage remineralisation. 3) Fluoride reduces the ability of plaque to turn into acid.
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Explain the term fluorosis.
When teeth are exposed to high levels of fluoride. The enamel gets white patches on it however it does not cause any health problems.
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2 reasons why people might be against adding fluoride to water.
1) Water should be as natural as possible. 2) People shpuld not be forced to take any artifical additives.
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What is the process of desalination?
Commonly described as reverse osmosis, sea water is filtered under pressure through a membrane that acts like a molecular filter letting onlysmall water molecules go through and keeping the sal back.
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4 disadvantages of desalination.
1) Uses a lot of energy because you need to generate high pressures. 2) Very expensive. 3)Generates a lot of green house gases. 4)High amounts of salt can be very acidic and needs to desposed of very carefulky.
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What is the process of distillation?
A mixture of 2 liquids is boiled, the liquid with the lowest boiling point turns into a gas and up into a condenser, it condenses into a liquid and is then collected in another beaker. The other liquidis left behind.
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How can pure water be obtained from sea water?
Through the process of distillation or desalination.
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What is a sloubility curve?
A graph that shows the solubility of a substance that varies with temperature. This is usually expressed as the maximum grams of substance that will dissolve in 100g of solvent.
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Definiton of the term solvent.
The liquid in which a solute is dissolved in to form a solution.
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Defnition of the term solute.
A chemical that can dissolve in a solvent.
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Definition of the term saturated.
When no more solute can dissolve in a solvent.
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What is hard water?
Hard water contains compounds such as calcium hydrogen carbonate, calcium sulfate, magnesium hydrogen carbonate or magnesium sulfate. Where as soft water contains no compounds.
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What is tempoary hard water?
This is where at room temperature it shows qualities of hard water however once it has been heated up it shows qualities of soft water,
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3 advantages of hard water
1) Strengthens teeth. 2)Reduces risk of heart disease. 3) Some people prefer the taste of it.
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3 disadvantages of hard water
1)Limescale on kettles makes them less efective, wastes energy. 2)Removing limescale can be expensive. 3)More soap is need to cause lather in hard water.
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How to tell the difference between hard and soft water.
Soap test. By having 2 water samples and a certain amount of soap the water sample that causes the least lather and soap is the heard water.
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Other cards in this set

Card 2

Front

Which 2 solutes are dissolved in water?

Back

Hydrogen and Oxygen

Card 3

Front

Guve examples of the ions that dissolve in water as it runs over or through the ground.

Back

Preview of the front of card 3

Card 4

Front

Name 2 of the most important gases dissolved in water.

Back

Preview of the front of card 4

Card 5

Front

Why is it inadvisable to drink untreated water from lakes and rivers?

Back

Preview of the front of card 5
View more cards

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