PROPERTIES OF WATER KL OCEANOGRAPHY UNIT II: OCEAN PLANET

IT’S A WATERY WORLD ABOUT 71% OF EARTH’S SURFACE IS COVERED BY H 2 O 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 H 2 O

EFFECTS OF HYDROGEN BONDS: PROPERTIES OF WATER CAUSED BY H+ BONDS LIQUID WATER LIQUID WATER H 2 O IS A LIQUID AT ROOM TEMPERATURE  WITHOUT H+ BONDS H 2 O WOULD BE A GAS/VAPOR COHESION/ADHESION COHESION/ADHESION H 2 O ABILITY TO STICK TO OTHER WATER MOLECULE (COHESION) OR TO OTHER SURFACES (ADHESION) VISCOSITY 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 SURFACE TENSION WATER’S RESISTANCE TO OBJECTS PENETRATING ITS SURFACE FILM THAT FORMS ON THE SURFACE OF THE WATER ICE FLOATS 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 SOLVENT WATER 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: CO 2 & O 2 TYPES: N 2, CO 2, & O 2 PRIMARILY IMPORTANCE: VITAL FOR PLANT & ANIMAL LIFE CO 2  NEEDED FOR PHOTOSYNTHESIS CO 2 + H 2 0  C 6 H 12 O 6 + O 2 PHYTOPLANKTON PRODUCE SUGAR(GLUCOSE) & OXYGEN TO FEED THE REST OF THE MARINE FOOD WEB CELLULAR RESPIRATION O 2 BREAKS DOWN FOOD AND PROVIDES ENERGY ZOOPLANKTON, FISH, INVERTEBRATES USE GLUCOSE TO MAKE CELLULAR ENERGY C 6 H 12 O 6 + O 2  CO 2 + H 2 0 FISH BREATH DISSOLVED O 2

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 O 2 RICH WATER TO OCEAN DEPTHS.

GASES IN OCEAN WATER: NITROGEN CYCLE IMPORTANCE: VITAL FOR PLANT & ANIMAL LIFE  N 2 IS “FIXED” INTO NITRATE (NO 3 -), NITRITE (NO 2 - ) AND AMMONIUM (NH 4 ) 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 (NH 4 ) & THE REST IS DISSOLVED IN THE H 2 O AND STAYS IN THE SOIL/SEDIMENT. MICROORGANISMS CONVERT NH 4 TO NO 3 - WHICH GETS BURIED IN THE SEDIMENT AND IS RELEASED ONCE AGAIN AS N 2 GAS

NITROGEN CYCLE-FILL IT IN!