Date post: | 15-Jun-2015 |
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Water Notes:
Water:
Composed of two hydrogen atoms and one oxygen atoms
H2OPolar Molecule
Polarity:
Unevenly distributed charges due to unequal forces placed on bonding electrons
Oxygen ends slightly negativeHydrogen end slightly positive
Results of Polarity:
Allows water to form Hydrogen Bonds
Result of Polarity:
Hydrophilic: All polar molecules attracted to water
Result of Polarity:
Hydrophobic: Repels non-polar substances such as water
Stabilizes Temperature:
Hydrogen bonds between molecules absorb heat energy, thus molecules do not move faster, therefore temperature does not rise as quickly
Need more heat energy to change temperature
Cohesiveness:
Hydrogen bonding locks molecules together
Surface Tension: Cohesion at the water’s surface
Cohesiveness:
Adhesion: when water attaches to non-water molecules
ADHESION
COHESION
Cohesiveness:
Capillary Action: Movement of water up
Universal Solvent:
Ions and polar molecules readily dissolve in water
Substances such as salt are pulled apart by attraction of opposite charges due to polar structures
Density:
Water has a density of 1g/mLOne of the few substances that is less
dense as a solid than liquidDue to hydrogen bonding and resultant
pockets
Seawater:
Seawater is slightly different due to the materials dissolved in it
These materials come from the chemical weathering of rocks on land and carried to the sea by rivers while the others are released into the ocean by hydrothermal vents
Solutes:
Solutes – dissolved materials98% of the solutes in sea water are
comprised of 6 ions (charged atoms)Of which 85% of the solids are comprised
of Sodium and Chloride, hence the salt taste
Salinity:
Total amount of salt dissolved in seawaterExpressed as number of grams of salt left
behind when 1,000g of seawater is evaporated
Effects on Organisms:
Slight changes in salinity can harm organisms
Some have developed adaptations to live in estuarine environments
Temperature:
The open ocean will range from -2° C and +30° C
Salt water freezes at a colder temperature than pure water
Density:
If it has more salt it is more denseIf it is colder it is more dense
Dissolved Gases:
The three most important gases for life are dissolved in the ocean:◦Oxygen◦Carbon Dioxide◦Nitrogen
Pressure:
The deeper you go in the ocean, the more pressure
This is due to all the weight of the water and air above you