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.