Chemical Oceanography Water (H 2 0)

WATER FACTS 75 % of the earth is covered with water. 75 % of the earth is covered with water. 97 % of earth’s water is in the oceans. 97 % of earth’s water is in the oceans. Only 3 % of the earth’s water can be used as drinking water. Only 3 % of the earth’s water can be used as drinking water. 75 % of the world’s fresh water is frozen in the polar ice caps. 75 % of the world’s fresh water is frozen in the polar ice caps.

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

One molecule Five “stuck “together

Water is a Polar Molecule Has both a negative and a positive side. Allows water molecules “join” together (raindrops, beading on surfaces) Hydrogen Bond

Water Exists As Three Different States: GAS SOLID LIQUID

Change of States The change from solid to liquid is called fusion, or melting. The change from liquid to ice is called solidification. The change from liquid to vapor is called evaporation. The opposite of evaporation (change from vapor to liquid) is called condensation.

Sublimation Change from vapor to a solid or solid to a vapor (although the change from vapor to solid is sometimes called deposition). eg. High ice clouds and dry ice

Heat Capacity Water changes state when it gains or loses heat. Water changes state when it gains or loses heat. Because of hydrogen bonding it takes a lot of heat energy to change its state. Because of hydrogen bonding it takes a lot of heat energy to change its state. Heat Capacity: the heat required to raise unit mass of substance by one degree of temperature. Heat Capacity: the heat required to raise unit mass of substance by one degree of temperature. Water has the highest heat capacity of any liquid or solid, except ammonia. Water has the highest heat capacity of any liquid or solid, except ammonia. Heat Capacity of water is defined as 1 calorie. Heat Capacity of water is defined as 1 calorie.

Water’s Heat Capacity About 5 X more heat must be added to water than to rocks to raise the temperature by 1C. On a hot day why the sand at the beach is so much hotter than the water. Why it takes so much longer to cook soup in a microwave than it does nachos. Why water was originally used as the coolant in your automobile, and as the primary fluid in your body.

Water pH Pure water has a pH of 7. Pure water has a pH of 7. Seawater with its dissolved minerals tends to be slightly basic, around 8. Seawater with its dissolved minerals tends to be slightly basic, around 8.

How much water do you use everyday? Follow the directions to calculate your daily water consumption. Follow the directions to calculate your daily water consumption. Convert your total consumption from US gallons to Liters (1L = 0.26 gallons). Convert your total consumption from US gallons to Liters (1L = 0.26 gallons). Complete the chart and three questions. Complete the chart and three questions.