PROPERTIES OF WATER
KL OCEANOGRAPHY
UNIT II: OCEAN PLANET
IT’S A WATERY WORLD
• ABOUT 71% OF EARTH’S SURFACE IS COVERED BY
H2O
• 96.5% IS OCEAN (SALT WATER)
• ONLY 2.5% IS FRESHWATER AND ONLY SOME OF THIS IS USEABLE BY HUMANS
WATER IS ESSENTIAL TO ALL LIVING THINGS
• ALL LIVING THINGS ARE 70-90% WATER.
• WATER IS A POLAR MOLECULE- HAVING A (+) AND (-) END
• INDIVIDUAL WATER MOLECULES ARE HELD TOGETHER WITH POLAR COVALENT BONDS.
• GIVES WATER A BOOM-A-RANG SHAPE
+ +
-
WHOLE MOLECULE: POLAR COVALENT WITH POLAR COVALENT BONDS THE SHARING OF ELECTRONS IS UNEQUAL.
• FOR OXYGEN:
• HAS 6 VALENCE ELECTRONS
• 2 OF THE 6 VALENCE ELECTRONS FORM COVALENT BONDS WITH 2 DIFFERENT HYDROGEN ATOMS
• 4 OF THE 6 VALENCE ELECTRONS AROUND OXYGEN FORM A CLOUD THAT PUSH THE H-O BONDED ELECTRONS DOWN INTO A 100˚ ANGLE
HYDROGEN BONDS: BETWEEN NEIGHBORING WATER MOLECULES
HYDROGEN BOND= WEAK ATTRACTIVE FORCE BETWEEN SLIGHTLY (+) HYDROGEN ATOM OF ONE MOLECULE AND SLIGHTLY (-) OXYGEN ATOM IN ANOTHER OR THE SAME MOLECULE.
• MANY HYDROGEN BONDS TAKEN TOGETHER ARE RELATIVELY STRONG.
• HYDROGEN BONDS CAUSE MANY OF UNIQUE
CHARACTERISTICS OF H2O
EFFECTS OF HYDROGEN BONDS:PROPERTIES OF WATER CAUSED BY H+ BONDS
• LIQUID WATER
• H2O IS A LIQUID AT ROOM
TEMPERATURE WITHOUT H+
BONDS H2O WOULD BE A
GAS/VAPOR
• COHESION/ADHESION
• H2O ABILITY TO STICK TO OTHER
WATER MOLECULE (COHESION) OR TO OTHER SURFACES (ADHESION)
• VISCOSITY
• TENDENCY OF A FLUID TO RESIST FLOW… IT’S THICKNESS
• COLD SYRUP SLOW V. WATER FASTER
EFFECTS OF HYDROGEN BONDS:PROPERTIES OF WATER CAUSED BY H+ BONDS
• SURFACE TENSION
• WATER’S RESISTANCE TO OBJECTS PENETRATING ITS SURFACE
• FILM THAT FORMS ON THE SURFACE OF THE WATER
• ICE FLOATS
• WATER BECOMES LESS DENSE AS A SOLID THAN AS A LIQUID BECAUSE H+ BONDS PULL THE MOLECULES INTO A CRYSTALLINE STRUCTURE THAT CAUSE THE MOLECULES TO SPREAD AND TAKE UP MORE SPACE
WATER- UNIVERSAL SOLVENTWATER IS UNIVERSAL SOLVENT, FACILITATES CHEMICAL REACTIONS BOTH OUTSIDE OF AND WITHIN LIVING SYSTEMS.
• SOLUTION= WHEN A SOLUTE IS DISSOLVED IN A SOLVENT
• SOLUTE= DRY SUBSTANCE THAT IS DISSOLVED BY A SOLVENT
• EX> SALT
• SOLVENT= LIQUID SUBSTANCE THAT DISSOLVES OTHER SUBSTANCES
COLLIGATIVE PROPERTIES OF OCEAN WATER (COMPARED TO FRESH WATER)
COLLIGATIVE PROPERTIES= PROPERTIES OF A LIQUID THAT ARE ALTERED BY THE PRESENCE OF A SOLUTE (LIKE SALT)
• RAISED BOILING POINT
• DECREASED FREEZING TEMPERATURE
• ABILITY TO CREATE OSMOTIC PRESSURE
• CONDUCTS ELECTRICITY
• SLOWED EVAPORATION
• DECREASED HEAT CAPACITY
GASES IN OCEAN WATER: CO2 & O2
TYPES: N2, CO2, & O2
PRIMARILY
IMPORTANCE: VITAL FOR PLANT & ANIMAL LIFE
• CO2 NEEDED FOR
PHOTOSYNTHESIS
CO2 + H20 C6H12O6 + O2
• PHYTOPLANKTON PRODUCE SUGAR(GLUCOSE) & OXYGEN TO FEED THE REST OF THE MARINE FOOD WEB
CELLULAR RESPIRATION
• O2 BREAKS DOWN FOOD AND
PROVIDES ENERGY
• ZOOPLANKTON, FISH, INVERTEBRATES USE GLUCOSE TO MAKE CELLULAR ENERGY
C6H12O6 + O2 CO2 +
H20
• FISH BREATH DISSOLVED O2
GASES FOUND IN OCEAN WATER
VARIES WITH DEPTH:
• MORE ABUNDANT AT THE SURFACE
• BASED ON THE AMOUNT OF RADIANT ENERGY AVAILABLE
VARIES WITH TEMPERATURE:
• WARM WATER HOLDS LESS DISSOLVED GAS THAN COLD.
• AS OCEAN WATER COOLS IT SINKS DUE TO DENSITY
DIFFERENCE, BRINGING O2
RICH WATER TO OCEAN DEPTHS.
GASES IN OCEAN WATER: NITROGEN CYCLE
IMPORTANCE:
VITAL FOR PLANT & ANIMAL LIFE
• N2 IS “FIXED” INTO NITRATE (NO3-), NITRITE
(NO2-) AND AMMONIUM (NH4) TO BE USED BY
AUTOTROPHS TO CREATE PROTEINS
• PROTEINS ARE MADE FROM AMINO ACIDS THAT ALL CONTAIN NITROGEN COMPOUNDS
• PASSED UP THE FOOD WEB THROUGH THE TROPHIC LEVELS
GASES IN OCEAN WATER: NITROGEN CYCLE
ASSIMILATION=WHEN PLANTS & ANIMALS USE NITRATE AND AMMONIUM TO CREATE PROTEIN & NUCLEIC ACID
• PLANTS USE SOME (NH4) & THE REST IS
DISSOLVED IN THE H2O AND STAYS IN THE
SOIL/SEDIMENT.
• MICROORGANISMS CONVERT NH4 TO NO3-
WHICH GETS BURIED IN THE SEDIMENT AND IS
RELEASED ONCE AGAIN AS N2 GAS
NITROGEN CYCLE-FILL IT IN!