Ocean Water Chemistry

How much salt?  Most places - 35 parts per thousand  Total amt of salt = SALINITY  Most Sodium Chloride  Salinity is lower – mouths of rivers  Evaporation increases salinity  Red Sea (high salinity)  Poles (high salinity – surface water freezes Leaving salt behind?

Why so salty?  Early history – ocean covered planet  Volcanoes erupted  Rain fell on land  Chemicals from rock = salt in ocean today

Effects of Salinity  Salt interfers with formation of ice crystals.  Higher density than fresh water  SO… mass of one liter of salt water is greater than mass of one liter of fresh water.  Density is simply the amount of mass packed in a unit volume.

Remember???  Volume = LxWxH _________ cm3 Amount of space something takes up MASS = Amount of matter (stuff) something is made up of (grams) Density = Amount of matter in a given space (MASS / Vol.) ______g/L or g/m3

So it is denser?  Seawater has greater buoyancy than freshwater.  ---- It lifts, or buoys up less dense objects floating in it.  Example – Egg floats in higher in salt water than in fresh water

Temperature of Ocean Water  Cold water is more dense thus it ????  Because warm water is less dense than cold water, warm water is only a thin layer on the ocean water.

Gases in Ocean  Carbon dioxide is 60 times more plentiful than in air.  Algae – photosynthesis  Corals – build hard skeleton  Oxygen – is scarcer in seawater than air.  Comes from photosynthesis (algae) & Air

Pressure?  Pressure increases with depth in ocean.  Scientist use a submersible which is built of materials which resist pressure to explore after 40 meters in depth.