PROPERTIES OF WATER

WATER IS THE MOST ABUNDANT COMPOUND IN MOST LIVIING THINGS WHAT KIND OF BONDS JOIN ITS ATOMS? ARE HYDROGENS JOINED TO HYDROGENS? WHY IS THE H END POSITIVE AND O END NEGATIVE?

POLARITY UNEQUAL CHARGES FORM IN A MOLECULE SINCE SHARED ELECTRONS ARE MORE LIKELY FOUND IN ONE AREA RATHER THAN ANOTHER IN WATER, THE O “END” IS MORE - AND THE H “END” IS MORE + THESE PARTIAL CHARGES ENABLE WATER TO DISSOLVE MANY OTHER POLAR MOLECULES AND IONIC COMPOUNDS

HYDROGEN BONDS WEAK BONDS FORMED FROM THE ATTRACTION OF OPPOSITE CHARGES EXAMPLE: IN WATER, THE POSTIVE END (H) IS ATTRACTED TO THE NEGATIVE END (O) OF ANOTHER WATER MOLECULE

COHESION ATTRACTION BETWEEN THE MOLECULES OF THE SAME SUBSTANCE

ADHESION ATTRACTION BETWEEN THE MOLECULES OF DIFFERENT SUBSTANCES http://www.sciencenewsforkids.org/articles/20030611/Note2.asp

SURFACE TENSION TENSION BETWEEN MOLECULES IS GREATER AT THE SURFACE DUE TO COHESION- FORMING A SURFACE FILM /

EXAMPLES OF SURFACE TENSION SOAP AND HOT WATER DECREASE SURFACE TENSION INCREASING ABILITY TO CLEAN MATERIALS http://www.ohs.osceola.k12.fl.us/teachers/animals/rljclizard

CLIMBING OR SPREADING DUE TO ADHESION CAPILLARY ACTION CLIMBING OR SPREADING DUE TO ADHESION AND COHESION

MIXTURES TWO OR MORE ELEMENTS OR COMPOUNDS PHYSICALLY MIXED BUT NOT CHEMICALLY COMBINED 1. SOLUTIONS - EVEN DISPERSION (EX. SALT WATER) A. SOLUTE - SUBSTANCE THAT IS DISSOLVED (SALT,...) B. SOLVENT - WHAT THE SUBSTANCE DISSOLVES IN (FREQUENTLY WATER); WATER IS THE GREATEST SOLVENT. IT DISSOLVES IONIC COMPOUNDS AND POLAR MOLECULES

NaCI Solution Cl- Cl- Na+ Na+ Water Water

ACIDS, BASES, AND pH WATER FORMS IONS H20  H+ AND OH- Oven cleaner WATER FORMS IONS H20  H+ AND OH- Bleach Ammonia solution Increasingly Basic Soap pH SCALE - INDICATES CONCENTRATION OF H+ IONS IN SOLUTION 7 – NEUTRAL; EQUAL CONCENTRATIONS ABOVE 7 - BASIC; MORE OH- BELOW 7 - ACIDIC; MORE H+ Sea water Human blood Neutral Pure water Milk Normal rainfall Acid rain Increasingly Acidic Tomato juice Lemon juice Stomach acid

IN A SOLUTION… ACIDS FORM HYDROGEN IONS BASES PRODUCE HYDROXIDE IONS BUFFERS - WEAK ACIDS OR BASES THAT REACT WITH STRONG ACIDS OR BASES TO PREVENT SHARP CHANGES IN pH