Chapter 3 Water and the Fitness of the Environment

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Chapter 3Water and the Fitness of the
Environment
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Inorganic Chemistry

• The study of inorganic compounds
• water
• acids
• bases

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Water

• Chemical formula H2O
• Properties
• cohesive, form H bonds
• adhesive, clings to surfaces
• polar

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Polarity of Water

• The molecule has opposite charges on opposite
  sides
• polar molecules form H bonds with other polar
  molecules

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Water is the Universal Solvent

• solution solvent solute(s)
• ex cup of hazelnut coffee
• (hot water, sugar, coffee grounds)

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WaterHydrophilic Bonding

• water molecules are attracted to molecules with
  an electrical charge
• affinity for water
• water-soluble
• H-bond formation

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WaterHydrophobic Bonding

• nonpolar compounds are repelled by water
• no affinity to water
• water-insoluble
• some vegetables and fruits with nonpolar
  pesticides

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Ionization of Water

• 2 H2O H3O OH --
• by convection
• H2O H OH --
• pH of pure water is 7

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pH

• Scale 0-14
• logarithmic scale
• compare pH 2 to pH 4

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Acids

• substances that increase H in solution
• pH below 7
• ex HCl H Cl --
• acid precipitation, with pH lt 5.6
• acid indigestion use antacids (tested in lab)

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Bases

• substances that reduce H in solution
• pH above 7
• ex. NH3 H NH4
• NaOH Na OH-

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Buffer

• prevent sudden pH changes
• raises pH by accepting H
• lowers pH by releasing H
• ex. Carbonic acid

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Buffer cont.

• in hi pH
• H2CO3 HCO3-- H
• in lo pH
• carbonic bicarbonate hydrogen
• acid ion
  ion

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Chapter 3

• THE END