WHAT IS IN SEAWATER? Kaitlyn Johnson Block 2A Marine Science
Jan 17, 2016
WHAT IS IN SEAWATER?
Kaitlyn Johnson
Block 2A
Marine Science
WHAT IS IN SEAWATER? By mass, seawater is about 96.5%
water and 3.5% dissolved substances (various types of salts.)
The world ocean contains 5.5 trillion tons of salts.
SALINITY IN SEAWATER Salinity- the total quantity (or
concentration) of dissolved inorganic solids in water.
The oceans salinity (by mass) is about 3.5%
Sodium and Chloride are the most abundant ions
SALINITY IN SEAWATER
2) How does the addition of ions to water change the properties of water?
(Salinity- measure if dissolved solids in sea water: (ex.) NaCl sodium chloride)
There are 4 ways the ions effect the water, which are calledColligative properties- “properties of solutions”
6
Heat & Cool
“Heat capacity of water decreases with salinity increasing”
-less heat is required in sea water than fresh water(more salinity, the faster it gets hot)-ex. boiling water
“As salinity increases, freezing point of water drops, and salt acts as a sort of anti freeze”
-ice forms at a lower temperature in sea water than freshwater-ex. lakes
Evaporation & Osmosis
-Water evaporates slower in sea water than fresh water-(e.x swimmers in a pool vs ocean drying)
“Dissolved salts attract water molecules, making evaporation slower”
“-Osmotic pressure -salinity’s different in environment verses salinity in a cell. -key factor of transmitting water in and out of cells”
THE LAW OF CONSTANT PROPORTIONS
Otherwise known as Forchahmmers principle
It is the law stating that aside from the water salinity there are always similaritys in other mixed minerals
WHAT ARE THE SOURCES OF THE OCEAN’S SALTS?
• Dissolved crustal rock (sodium)• Breaking up of the cooled igneous rocks of the Earth’s
crust • Volcanoes
• Solid and gaseous materials that escaped from the earths crust through volcanic vents
• Rift vents
Chemical EquilibriumBy Jimmy DeLuca
What is it?Chemical equilibrium- The proportions and
amounts of dissolved salts per unit of volume.Whatever goes in the ocean must come out.Ions are added to the ocean at the same rate
that they are being removed.Dissolved particles are brought down into the
sediment at the bottom of the ocean.This theory helps explain why the ocean is
not growing saltier.
THE 3 MAIN GASESBy Erin Bieger
NITROGEN About 48 percent of dissolved gas in
seawater is nitrogen. Upper layers of ocean water are
saturated with nitrogen gas. Percent of gas in atmosphere Nitrogen- 78.08%Atmosphere
OXYGEN About 38 percent of gas dissolved in the
ocean is oxygen. The small amount of oxygen is vital
resource for animals that extract oxygen in the gills.
Percent of gas in atmosphere O- 20.95% Atmosphere
CARBON DIOXIDE The amount of carbon dioxide in the
atmosphere is small because CO’2 is a great demand by photosynthetic plants.Percent of gas in atmosphere
CD-0.035% Atmosphere ,respiration
ACIDITY AND ALKALINITY
By: Kaitlyn de la Torre
IMPORTANCE OF ACID AND ALKALINE IN SEA
WATER Sea water is slightly Alkaline, its average PH is
about 8.0. The ocean acts as a buffer, if more acid is added
to the ocean it produces more alkaline to keep the PH balanced.Similar to homeostasis
If Sea water was too acidic seashells and coral reefs would weaken and dissolve.
Acidity is important in sea water because it decays bacteria and remains of animals.