"Water is the best of all things'" Pindar c' 522 BC c' 438 BC, Olympian Odes

1

• "Water is the best of all things." - Pindar (c.
  522 BC - c. 438 BC), Olympian Odes
• Civilization began around wetlands today's
  civilization has every reason to leave them wet
  and wild." - Edward Maltby, Waterlogged Wealth,
  1986.

2
Quiz

• K I - dissolves in water. please diagram how the
  the ions are stabilized in solution.

• Please compare a bromine atom and a bromide ion.
  In terms of electrons and protons, emphasizing
  the charge magnitude and sign

3
Where we are

• Today we will cover to the end of the chapter
• You should work all problems and concept
  problems
• Start exploring Extensions problems 49-60
• Choose one of 50,51,52 and one of 54,55,56 to
  turn in by Tuesday, each on it own card.
• Due dates for paper

4
Solubility of Non conducting compounds

• When we dissolve sugar It does not break into
  Ions
• Individual molecules of sugar are solvated by the
  water. (See Figure 5-16 through 18 on page 241)
  
• The electronegative oxygen atoms in the sugar
  molecule provide the polarity for the molecules
  to dissolve

5
Solubility of Non Ionic compounds


NButanol (1-Butanol) solubility 9 g / 100 ml
t-butanol (1,1-dimethyl-1-ethanol)solubility
Soluble in all proportions
6
Water Solubility

• Molecules that do not have Oxygen or nitrogen in
  them in sufficient quantities will not dissolve.
  
• Vegetable oils
• Hydrocarbons
• Polyhalogenated compounds.

7
Soap
8
Experiment

• Find a piece of flat glass
• Clean it well with soap and water and then rinse
  well. Let it dry
• Place a drop of water on the glass.
• Describe how it looks
• add another drop of water
• Describe how it looks
• Mix up an 8 glass of water with 1 tsp of dish
  washing liquid. (your could do this while the
  glass is drying in the second step.)
• add one drop of the soap mixture to the water on
  the plate and describe what happens.

9
Surface Water Treatment
10
Charleston SC water treatment Facility
11
Water Treatment

• Intake Screening removes large debris from
  water
• Aeration The water is mixed to liberate
  dissolved gases and to suspend particles in the
  water column.
• Flocculation The materials and particles present
  in drinking water (clay, organic material,
  metals, microorganisms) are often quite small and
  so will not settle out from the water column
  without assistance. To help the settling process
  along, "coagulating" compounds are added to the
  water, and suspended particles "stick" to these
  compounds and create large and heavy clumps of
  material.
• Sedimentation The water is left undisturbed to
  allow the heavy clumps of particles and
  coagulants to settle out.

12
Water Treatment

• Filtration The water is run through a series of
  filters which trap and remove particles still
  remaining in the water column. Typically, beds of
  sand or charcoal are used to accomplish this
  task.
• Disinfection The water, now largely free of
  particles and microorganisms, is treated to
  destroy any remaining disease-causing pathogens.
  This is commonly done with chlorination (the same
  process used to eliminate pathogens in swimming
  pools), ozone, or ultraviolet radiation. The
  water is now safe to drink and is sent to pumping
  stations for distribution to homes and
  businesses.

13
TriHalomethanes

• CHCl3, CHCl2Br, CHClBr2,CHBr3
• By products of using chlorination for water
  purification.
• Organic material is halogenated in the process of
  chlorination
• Ozonation prevents this

14
Water Treatment
15
Access to safe drinking water varies widely
across the world
5.14
16
Two water purification techniques
Reverse osmosis
Distillation
5.14