Transcript pH Ionization and Hydrogen Bonding

pH Ionization and Hydrogen Bonding
pH
 pH is the concentration of hydrogen ions in a solution
Strong Acid and Base
 HCl – hydrochloric acid
 Strong acid
 H+ loses electron to Cl Solution would have a HIGH concentration of H+ ions
 NaOH – sodium hydroxide
 Strong base
 Na+ loses electron to OH Solution would have a HIGH concentration of OH- ions
Buffers
 Weak acids/bases that react with strong acids or bases to have
a gradual shift in the pH scale
 Ex: Milk calming stomach acid
Why is water neutral?
 The molecule of H2O separates into
 H+ loses electron to OH Equal parts of each ion
 H2O has a neutral pH of 7
pH scale
Demonstration
 Are the pieces of paper without water more attracted to each
other?
 Why are the pieces of paper with water easier to stick
together?
 What is holding the papers together?
 Water is a polar molecule
 Partial negative pole and partial positive side
Hydrogen bonding
 Due to partial positive and partial negative poles on the
water molecule, other water molecules are attracted to each
causing a hydrogen bond
 Not as strong as covalent or ionic bonding
Hydrogen Bond
 http://programs.northlandcollege.edu/biology/Biology111
1/animations/hydrogenbonds.html
 What are the other unique properties of water?
Cohesion
Cohesion – Surface Tension
Adhesion
Adhesion - Capillary Action
 How water moves up plants
 Plant tubes (xylem) are made of cellulose which is polar
 Water molecules are attracted to the sides of thin tubes of
xylem
What do you
think will happen
to the daisies?
Capillary Action
 How water moves up
plants
 Water molecules are
attracted to the sides
of thin tubes plant
walls
 This is also why water
moves up a straw
without you doing
anything!
Activity!
 Drops of water on a penny
 What properties of water are shown in this experiment?