WARNING DHMO ACTS AS A PERFORMANCE ENHANCER

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WARNING! DHMO ACTS AS A PERFORMANCE ENHANCER!

• All professional athletes readily admit use of
  this substance.
• Common additive in beverages.
• Global warming increasing levels of DHMO in
  coastal cities.
• DHMO linked to winter auto accidents.
• DHMO implicated in worldwide deaths.
• Industrial solvent
• Invisible killer!
• DHMO sank Titanic!
• Threat identified

DIHYDROGEN MONOXIDE
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Bubbles
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• A Treatise
• on the Unique Properties of Water

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Water Review
Life and importance Of water
Origin of life
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General Physical Properties 638
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• MAJOR PROPERTIES
• POLAR
• FORMS H-BONDS
• ADHESIVE
• COHESIVE
• HIGH SURFACE TENSION
• HIGH HEAT OF VAPORIZATION
• HIGH SPECIFIC HEAT
• EXPANDS AS SOLID
• VERSATILE SOLVENT
• UNUSUAL PHASE CHANGE
• DISSOCIATION AND IONIZATION

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P o l a r i ty
Effects of Molecular structure
Tetrahedron w/ 4 orbitals e-s around O mostly
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KINETIC ENERGY HEAT TEMPERATURE CALORIE (cal)
(c) KILOCALORIE (kcal) (C) 100C (212F) 37C
(98.6F) 23C (72F) 0C (32F)
Heat Capacity and Climatic effects
Latent heat Changes of State
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Scale conversions C 5(F
-32) 9 F 9C 32 5 K
C 273
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Formation of H-bonds releases heat energy is
stored in bonds Liquid gtice Breaking of bonds
absorbs heat Ice gt liquidgtgas
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HIGH HEAT OF FUSION heat removed to change water
to ice temperature does not change, only state 80
calories /gram Lakes difficult to freeze Release
heat as they do Effect? (only ammonia is higher)
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H20 liquid - H-bonds pull H2O molecules together
dense, compact H2O solid - frozen in place bond
angles lattice structure holes! Water is
densest at 4 degrees Celcius ice is less dense
than water floats!
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FREEZING POINT IS HIGH 0C - basis of Celsius
scale liquid has 15 more bonds than solid If
normal - would be a gas at room temperature No
lakes, no rain, no body fluids!
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High Heat Capacity/Specific Heat BAKED POTATO
EFFECT once heated, slow to cool or vice
versa Can absorb extreme amt. of heat -2C - 35C
oceans -70C - 57C land moon -155C - 135C
Why? Heat buffer- absorbs, transfers
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SPECIFIC HEAT Amount of energy required to
change the temperature of 1 gram of water 1
degree C. Energy in calories c
1 calorie/gram/ C 1c/g/ C
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Boiling breaks bonds requires energy input Very
high due to cohesion 100C - usually ??? Basis
of Celsius scale
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High Heat of Vaporization add heat energy to
increase temp 1 calorie raise 1 gram,
1C 0--gt100 100 calories liquid to gas 540
calories/gram no temperature change, only
state Hard to boil
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Water cools at surface more quickly as more
energetic water molecules escape(vaporize) and
take heat w/ them Sweating cools body by
evaporation Due to random motion some have more
energy escape along w/ their heat energy
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Surface tension
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Water molecules surrounded by other water
molecules - bonded At surface fewer exposures,
stronger bonds to one another Rapid breaking
/reforming cohesion Surface more difficult to
break Jesus lizard feet move too fast!
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Adhesion -- clinging to other surfaces Capillarity
effect?
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Xylem and Phloem of plants
Capillarity
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UNIVERSAL SOLVENT
Dissolves more substances than any other
liquid CAN DISSOLVE ANY SUBSTANCE W/ NET
ELECTRICAL CHARGE, BOTH IONIC AND POLAR COVALENT
NOT NON-POLAR OIL/FATS NO CHARGE, NO
ATTRACTION MAY REPEL
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Grey sodium Green chlorine
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Negative Oxygen regions of polar water
molecules are attracted to sodium cations (Na).

Na






Na
Positive hydrogen regions of water molecules
cling to chloride anions (Cl).



Cl
Cl








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A water-soluble protein
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• HYDROPHYLLIC -
• Charged regions of H2O attracted to other
  charged areas
• Polar compounds (generally) soluble
• Ionic compounds - dissociate ----gt charged ions
  in water
• some large hydrophyllics can absorb water not
  dissolve

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HYDROPHOBIC- NONPOLAR (SYMMETRIC CHARGE) NOT
SOLUBLE IN WATER
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• Most biochemical reactions in water
• Usually as solutes in solution
• Solute concentration
• Molecular wt sum of weight of all atoms in
  molecule
• Mole amt.of substance w/mass(g) equivalent to
  m.wt.
• Example C12H22O11
• C12 H1 O 16 (daltons)
• Total 342 daltons--gt 342 g
  Molarity moles/ liter
  342 g in 1 liter water

Water Review
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The pH scale and pH values of some aqueous
solutions
Strong and Weak acids And bases
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Dissociation of water
Arhennius and Pure water
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Acids, Bases and pH

• -the oxygen atom in water tends to grab
  electrons in the molecule , the H are only
  loosely held
• -water molecules swap hydrogen protons
• -When one water molecule picks up a H it
  momentarily becomes . 
• -The water molecule that looses the proton
  momentarily becomes negatively charged

http//web.jjay.cuny.edu/acarpi/NSC/7-ph.htm
http//web.jjay.cuny.edu/acarpi/NSC/7-ph.htm
Proton xchg
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pH H2O H20 lt---gt H3O OH- DISSOCIATION H
HYDROGEN ION OH- HYDROXIDE ION H3O
HYDRONIUM ION H2O lt---gt H OH- At equilibrium
water is NOT ionized
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PURE WATER ACID
PURE WATER
Neutral Solution H3O OH-
Acid Solution H3O gt OH-
acid - a proton donor, a chemical that increases
the concentration of hydronium ions in
solution.  base - a proton acceptor, a chemical
that reduces the concentration of hydronium ions
in solution (and increases the concentration of
hydroxide ions).
Proton xchg
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Result of exchange
-at any given moment 2 water molecules out of
every 1 billion are split into a positively
charged H3O (called hydronium) ion and a
negatively charge OH- (called hydroxide) ion. 
-In a sample of pure water, the concentration of
hydronium ions is equal to 1 x 10-7 mole per
liter (0.0000001 moles per liter).  -In pure
water, the number of hydronium ions equals the
number of hydroxide ions, so the concentration of
hydroxide ions must also equal 1 x 10-7 moles per
liter (moles per liter can be abbreviated M). 
-This equilibrium between hydronium and
hydroxide ions can shift if we mix other
substances with water.
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BUFFERS

• Buffer are compounds that resist changes in
  hydronium ion and the hydroxide ion concentration
  upon addition of small amounts of acid or base,
  or upon dilution.
• Tend to neutralize organic solutions homeostasis
• pH increases, H is added, shift to right
• pH decreases, H removed, shift to left

Carbonic Acid H donor
H acceptor Base
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BUFFERS Minimizes sudden changes in
pH Combinations of Hdonor and Hacceptor Accept
excess H in soln. Donate H when depleted EX
bicarbonate buffer H2CO3 lt---gt HCO3- H HCl
NaHCO3 --gt H2CO3 NaCl NaOH H2CO3 ---gt
NaHCO3 H20
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Overall lessons

• Many properties of water are emergent properties
  due to hydrogen bonding.
• The cohesion of water molecules to each other is
  exploited by plants and animals.
• Water resists temperature changes by absorbing
  lots of heat.
• Lower density of ice causes it to float
  insulate the water below.
• The polarity of water allows it to dissolve other
  polar molecules.
• Non-polar compounds are hydrophobic and not
  easily dissolved in water.
• A mole of a compound has a constant of
  molecules.
• Adding or removing hydrogen ions changes the pH
  of a solution.
• Buffers resist pH changes by accepting or
  donating H ions when H changes.

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• The following are pH values cola-2 orange
  juice-3 beer-4 coffee-5 human blood-7.4. Which
  of these liquids has the highest molar
  concentration of OH-?
• cola
• orange juice
• beer
• coffee
• human blood

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• Based on your knowledge of the polarity of water,
  the solute molecule is most likely

• positively charged.
• negatively charged.
• neutral in charge.
• hydrophobic.
• nonpolar.

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• How many grams of the molecule in this figure
  would be required to make 1 L of a 0.2 M solution
  of the molecule? (Carbon 12, Oxygen 16,
  Hydrogen 1)

• 8
• 12
• 24
• 32
• 60

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• If the pH of a solution is increased from pH 8 to
  pH 9, it means that the
• concentration of H is 10 times greater than
  what it was at pH 8.
• concentration of H is 100 times less than what
  it was at pH 8.
• concentration of OH- is 10 times greater than
  what it was at pH 8.
• concentration of OH- is 100 times less than what
  it was at pH 8.
• concentration of H is greater and the
  concentration of OH- is less than at pH 8.

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• Acid precipitation has lowered the pH of a
  particular lake to 4.0. What is the hydroxide ion
  concentration of the lake?
• 10-7 M
• 10-4 M
• 10-10 M
• 10-14 M
• 10 M