Chemistry of Life – Part II – Properties of Water
Water
Held together with Hydrogen Bonds
~ an attraction between ______
~ ______bonds
~ help hold large molecules together
(organic compounds like ______)
~ gives water its unique properties like cohesion and adhesion!!
What are the 5 UNIQUE properties of water? Why are they important?
1. surface tension due to cohesion (has a “______”) ~ ______
2. adhesion causes capillary action (creeps up thin tubes) ~ plants (drawing water through ______)
3. expands when it freezes (it ______) ~ water in lakes/ponds does not fully ______
4. evaporates slowly ~ helps organisms keep ______
5. resists temperature change ~ stable environment for organism, regulate ______
Mixtures – 2 or more elements/compounds mixed but ______chemically combined
- they can be separated without chemicals
ex: ______
Two types of mixtures involving water:
a. solutions- uniformly dissolved, usually ______
Two parts of any solution involving water:
* solute- substance being dissolved (ex: ______)
* solvent- substance doing the dissolving
______– “universal solvent”
b. suspensions- large ______of molecules floating/suspended in a liquid
Solution (______dissolving in water) Suspension (______in water)
Solute: ______
Solvent: ______
Acids
form hydrogen ______(H+) in water (contain ______concentration of H+ ions than pure water)
- have pH ______7
Bases
form hydroxide ions (OH-) in water (contain ______concentration of H+ ions than pure water)
- have pH ______7
pH (potential hydrogen) scale
mathematical scale used to determine the concentration of H+ to OH- ions
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
_____ acidic ______acidic
_____ basic solution ______basic
_____ H+ ions ______numbers of H+ and OH- ______H+ ions
______OH- ions ______OH- ions
Buffers
weak acids or bases that can react with strong acids or bases to ______the pH.
The pH of fluids in most human cells must remain between ______
If too high or too low, necessary ______cannot occur
Exception = ______– necessary to break down foods into absorbable molecules
Buffers will be ______just after the stomach