Why is water so important to life?

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Why is water so important to life?
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Extraordinary Properties of Water

• Cohesion
• Water molecules stick together
• Surface tension
• Adhesion
• Water molecules cling to other solids
• capillarity

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Extraordinary Properties of Water

• High Specific Heat
• Amount of heat that must be absorbed for 1g to
  change 1o C for water 1.00 cal/g/oC

• Sp Heat of common liquids
• Liquid SpHt (cal/g/oC)
• Ammonia 1.23
• Water 1.00
• Eth alc 0.60
• Acetone 0.53
• Olive oil 0.47
• Mercury 0.03

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Extraordinary Properties of Water

• High Heat of Vaporization
• (change from liquid to gas)
• Quantity of heat a liquid must absorb for 1g to
  be converted to the gas state for water 576
  cal/g

• Ht of Vap of some liquids
• Liquid Ht Vap (cal/g)
• Water at 37C 576
• Ammonia 302
• Eth alcohol 237
• Acetone 125
• Mercury 59

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Extraordinary Properties of Water

• Water Expands when freezing
• Ice Floats!
• Water is most dense at 4oC, and expands just a
  bit to form ice crystals

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Extraordinary Properties of Water

• Water is a versatile solvent
• Ionic compounds dissolve in water
• Covalent compounds rich in O or N dissolve in
  water

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Extraordinary Properties of Water

• Adhesion and Cohesion
• High Specific Heat
• High Heat of Vaporization
• Expands when freezing
• Versatile Solvent

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How does water do all this?What allows water to
facilitate life at the cellular and global level?
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Hydrogen Bonds

• A weak force of attraction between the H on one
  molecule and a highly electronegative atom on
  another molecule

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Extraordinary Properties of Water

• Versatile Solvent-------due to polarity
• Adhesion and Cohesion---due to H bonds
• High Specific Heat --------due to H bonds
• High Heat of Vap. ---------due to H bonds
• Expands when freezing ---due to H bonds

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Ahh, water!