2. Water = 2 Hydrogen atoms + 1 Oxygen atom “H2O”

3. H-Bonds Continued: Water
H-Bonds are why water
molecules stick together
so well to each other and
other materials. Also…
Pg 41

4. H-Bonds Continued: Water

5. Learning Objectives:
Tell the connection between a solvent, solute and solution (Pre-AP only)
Tell the connection between Hydroxide ions and hydrogen ions
Tell what the connection between Acids, Bases and Water
Know how to read the pH scale and it recognize its unique properties

6. Phases of matter: Chemistry in liquids Solid Liquid Gas
all are important for life but which would you think is the most important?
Liquid: cells are mostly water (H20) so that’s where most biological reactions (rxn) occur
Chemistry in liquids
Solution –liquid containing 2 or more chemical compounds
solute
solution
Solvent –(in a solution) a chemical that can dissolve other compounds (usually liquid)
Solute –(in a solution) a chemical that is dissolved (usually solid)
solvent

7. What is the most important solvent for all living things?
Water (DUH!)
Also Remember that it
has polar covalent bonds O H δ+ δ- O H δ- δ+
Water: “the Break-down”
H+1
OH-1 +
hydrogen
ion
hydroxide

8. + H+ OH- H2O O H [H+] = concentration of hydrogen ions
Water cont.. H+
hydrogen ion
OH- +
hydroxide ion
H2O +
No e- s left +1 O H -1
Acid: any compound that, when dissolved in water, increases [H+]
Base: any compound that, when dissolved in water, increases [OH-]
[H+] = concentration of hydrogen ions
[OH-] = concentration of hydroxide ions

9. pH : measure of [H+] or [OH-] scale of 1  14 Acid  Base

10. More Acidic [H+] > [OH-] [H+] = [OH-] (Pure H2O) Neutral More Basic
pH scale
More
Acidic
[H+] > [OH-]
[H+] = [OH-]
(Pure H2O)
Neutral
More
Basic
[H+] < [OH-]

11. Power of the pH Scale: The pH scale is a logarithmic scale so the units are NOT equally spaced like you’d normally see
1000x
More Acidic
than pH = 6
pH = 3
pH = 6
pH = 5
pH = 4
pH = 3
pH = 2
pH = 1
10x more
acidic
Equal
Spacing
pH = 4
100x
more
acidic
10x more
acidic
pH = 6
pH = 5
10x more
acidic

13. END