Chemical Chemical OceanographyOceanographyWater (HWater (H220)0)

WATER FACTSWATER FACTS 75 % of the earth is covered with 75 % of the earth is covered with

water.water. 97 % of earth’s water is in the 97 % of earth’s water is in the

oceans. oceans. Only 3 % of the earth’s water can Only 3 % of the earth’s water can

be used as drinking water. be used as drinking water. 75 % of the world’s fresh water is 75 % of the world’s fresh water is

frozen in the polar ice caps.frozen in the polar ice caps.

Molecular Structure of Molecular Structure of WaterWater

Each hydrogen Each hydrogen atom is atom is covalently covalently bonded to the bonded to the oxygen via a oxygen via a shared pair of shared pair of electrons. electrons.

One moleculeFive “stuck “together

Water is a Polar Water is a Polar MoleculeMolecule Has both a negative Has both a negative

and a positive side.and a positive side. Allows water Allows water

molecules “join” molecules “join” together (raindrops, together (raindrops, beading on beading on surfaces)surfaces)

Hydrogen Bond

Water Exists As Three Water Exists As Three Different States:Different States:

GAS

SOLID

LIQUID

Change of StatesChange of StatesThe change from solid to liquid is called The change from solid to liquid is called

fusionfusion, or melting., or melting.The change from liquid to ice is called The change from liquid to ice is called

solidificationsolidification..The change from liquid to vapor is called The change from liquid to vapor is called

evaporationevaporation..The opposite of evaporation (change The opposite of evaporation (change

from vapor to liquid) is called from vapor to liquid) is called condensation.condensation.

SublimationSublimationChange from vapor to a solid or solid to a Change from vapor to a solid or solid to a vaporvapor (although the change from vapor (although the change from vapor to solid is sometimes called deposition). to solid is sometimes called deposition).

eg. eg. High ice clouds and dry iceHigh ice clouds and dry ice

Heat CapacityHeat Capacity Water changes state when it gains or loses Water changes state when it gains or loses

heat.heat. Because of hydrogen bonding it takes a lot Because of hydrogen bonding it takes a lot

of heat energy to change its state.of heat energy to change its state.

Heat Capacity: the heat required to raise Heat Capacity: the heat required to raise unit mass of substance by one degree of unit mass of substance by one degree of temperature.temperature.

Water has the highest heat capacity of any Water has the highest heat capacity of any liquid or solid, except ammonia. liquid or solid, except ammonia.

Heat Capacity of water is defined as 1 Heat Capacity of water is defined as 1 calorie.calorie.

Water’s Heat CapacityWater’s Heat Capacity About 5 X more heat must About 5 X more heat must

be added to water than to be added to water than to rocks to raise the rocks to raise the temperature by 1C.temperature by 1C.

On a hot day why the sand On a hot day why the sand at the beach is so much at the beach is so much hotter than the water. hotter than the water.

Why it takes so much longer Why it takes so much longer to cook soup in a microwave to cook soup in a microwave than it does nachos. than it does nachos.

Why water was originally Why water was originally used as the coolant in your used as the coolant in your automobile, and as the automobile, and as the primary fluid in your body. primary fluid in your body.

Water pHWater pH

Pure water has a pH Pure water has a pH of 7.of 7.

Seawater with its Seawater with its dissolved minerals dissolved minerals tends to be slightly tends to be slightly basic, around 8.basic, around 8.

How much water do How much water do you use everyday?you use everyday?

Follow the directions to calculate Follow the directions to calculate your daily water consumption.your daily water consumption.

Convert your total consumption from Convert your total consumption from US gallons to Liters (1L = 0.26 US gallons to Liters (1L = 0.26 gallons).gallons).

Complete the chart and three Complete the chart and three questions.questions.