Zusammenfassung der Ressource
Water
- Treatment
- Chlorine
- Advantages: -Kills microbes/pathogens in water
- Disadvanatges: -Reacts with
harmless organic molecules, forming
TOXIC/POISONOUS products
- Flourine
- Advantages: -Nobody
has proved it has
negative affects apart
from fluorosis.
-Fluoridation shows 30%
reduction in teeth cavities
-Prevents heart disease
- Disadvantages: -In excess can weaken teeth
-Can cause fluorosis -Some people are against
mass medication -Water has to be monitored
as it may already contain a lot of fluoride.
- Water from resevoir
- Screening
- Removal of solids and microbes
- Filtration
- Chlorination
- Houses
- Pure Water: -Take
water that is fit to drink.
-Distil it by boiling.
-Turns to gaseous
steam which is cooled
to condense. -This is
collected.
- Home Filters: -Filters
that contain silver to
kill bacteria -Carbon
to absorb impurities -
Ion exchange resins
to soften water.
- Permanent Hard water
- Hard water: Formed when CALCIUM
and/or MAGNESIUM ions dissolve in water
- Scum
- The m+c ions
REACT WITH
SOAP
- Insoluble, cloudy substance
that floats on the water
- Can get soapless
detergents
- Benefits: -Ca2+ good for teeth and bones
-Less risk of developing heart disease
-Improves taste
- Drawbacks: -Scum, need more soap to have the
same cleaning affect therefore more money
-Scum is unsightly on baths etc. -Scale reduces
efficiency of heating systems and insulates the
heating element in kettles, taking longer to boil
- Temporary Hard Water
- HYDROGEN CARBONATE ions - HCO3
- Can be removed by
boiling. The HCO3
decomposes to form
insoluble calcium
carbonate - limescale
- Scale
- Insoluble solid
- When temporary
hard water is BOILED
- Get water softners
- Softening Hard Water
- Softened by SODIUM CARBONATE
- the carbonate ions react with the
Ca2+ and Mg2+ ions to make an
INSOLUBLE PRECIPITATE
- Ion Exchange
Columns: SODIUM or
hydrogen ion resin in
the columns,
EXCHANGES them for
the Ca or Mg ions