1. Chemistry of Water

2. Structure 1 oxygen + 2 hydrogen Oxygen end is negatively charged
Hydrogen ends are positively charged

3. Hydrogen Bonds
Hydrogen Bonds: weak bonds that form between the O and H of different water molecules

4. 1. Polarity Polarity: water has an uneven distribution of charge
Held together by covalent bonds
Gives water special properties

5. Hydrophilic
Hydrophilic: Water LOVING
Will dissolve in water

6. Hydrophobic
Hydrophobic: Water FEARING
Will not dissolve in water

7. 2. Universal Solvent
Universal Solvent: Most solids and gases will dissolve in water because it is a polar molecule

8. 3. Cohesion
Cohesion: Water molecules are attracted to other water molecules

9. Results of COHESION
Surface Tension: The surface of a liquid resisting an external force because of the hydrogen bonding of water molecules

10. 4. Adhesion Adhesion: Water sticks to other molecules
Water ADHERES to things

11. Results of ADHESION
Capillary Action: Water “climbs” up the surface of other molecules

14. 5. High Heat Capacity
High Heat Capacity: water can hold its temperature
Regulates temperature inside living cells
Regulates temperature in the air and in the oceans

15. 6. Density
Density: because of the shape of water molecules, ice is less dense when it freezes
Why would this be important to organisms that live in water?

16. 7. pH pH scale: a measure of the acidity of a solution
Water has a pH of 7
Most organisms need a pH between 5-7

17. Acids and Bases
Ionization of water: as water molecules bump into each other, they lose or pick up a proton

18. Acids and Bases
Hydroxide Ion: OH⁻
Hydronium Ion: H₃O⁺

19. Acids
Acids: the number of hydronium (H₃O⁺) ions in a solution is greater than the number of hydroxide (OH⁻) ions
H₂O  H⁺ + OH⁻
Hydrochloric Acid
H⁺ + Cl⁻  HCl

20. Bases
Bases: the number of hydroxide (OH⁻) ions in a solution is greater than the number of hydronium (H₃O⁺) ions
H⁺ + H₂O  H₃O⁺
Sodium Hydroxide
Na⁺ + OH⁻  NaOH

21. Solutions
Solution: a mixture of one or more substances are equally distributed in another substance
Solute: the substance dissolved that gets dissolved
Solvent: the substance in which the solute is dissolved in