Cards (3)

  • State the characteristics of water
    • High boiling point- hydrogen bonding, useful for organisms with a hydroskeleton, water in bodies
    • Ice less dense than water, unlike most liquids in the solid state. hydrogen bonds fix the positions of the water molecules further apart, insulating layer on ponds
    • Cohesive (plants)
    • Adhesive (capillary action- water rises up narrow tube against gravity)
    • Coolant- buffers temp changes, for enzymes only active in narrow temp ranges
    • Stable- provides constant enviro (high SLH vaporisation)
    • Surface tension of water strong enough to support small insects
    • water has high density/similar density to living organisms so organisms can float/buoyancy
  • why is water polar?
    • dipole exists between hydrogen and oxygen atoms
    • causes H to have δ+\delta+ charge and O an δ\delta- charge
    • do not share electrons equally in a covalent bond- oxygen attracts electrons more strongly (more electronegative)
  • True or false? hydrogen bonds are relatively weak interactions which break down constantly between water molecules
    TRUE- however since water has MANY H bonds it still have a high SHC