properties of water marine science notes series. water molecule and bonding forces i. london forces:...
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Properties of Water
Marine Science Notes Series
Water Molecule and Bonding Forces
I. London Forces: Intramolecular a) Covalent Bonds: sharing of electrons
between Hydrogen and Oxygen
b) Van der Waals – forces within the water molecule
c) Hydrogen Bonds – keeping a network of water molecules together (~105 0 angle)
Energy & Water• Heat Values are measured in calories and
joules. a) a calorie is the amount of heat energy needed to raise the temperature of 1 gram of water by 10C
This is sometimes called specific heatb) There are energy values when water changes state from a solid to a liquid to a gas(Latent Heat of… Fusion and of Vaporization)c) Temperature is an indirect function of heat energy
F= 9/5 C + 32C = 5/9 (F – 32)
Specific Heat of Salt Water?
• We will calculate the specific heat of salt water, but will see how accurate we are by determining the specific heat of a known metal
Heat Loss or Gain = m (Cp) T
Cp = Specific Heat
Special Properties of Watera) Water can break salts down into ions
(which are charged particles) Cations are positive ionsAnions are negative ions
b) Cohesion – This holds a water molecule together as a “body”
c) Adhesion – the ability of water to bond with other molecules
d) Viscosity – the ability of a liquid to flowe) Density – varies with temperature*
Seawater
• The density of seawater at 4 oC is approximately 1.0278 g/cm3
• The freezing point of seawater is -1.33 oC
• Open ocean water has a salinity of 35 g/kg
Eleven Major Constituents
• Chloride• Sulfate• Bromide• Bicarbonate• Fluoride
• Boron• Strontium• Calcium• Potassium• Magnesium• Sodium
Residence Time of Chloride is 80 million years
Residence Time of Sodium is 60 million years
Light and Seawater• Visible light ranges from 350 to 720 nm as
part of an electromagnetic light visibl emission
-In the first 1 meter – 60% of light is absorbed
-In the first 11 meters, 80% of light is absorbed
-Below 1000 m, no light penetrates
Attenuation
Nature Reviews Microbiology 2007
Gases in water
• Solubility is determined by – Temperature– Salinity – Density
It is measured in mg/L or ppm. The understood gases are Oxygen and Carbon dioxide