Water and its properties

- The water molecule is polar (oxygen (partially negative) draws the hydrogen (partially positive) molecules towards itself)
➟ water molecules is a polar covalent molecule (covalent = they share electrons)
- The unequal distribution is called a dipole moment. And water molecules interact with each other with hydrogen bonds.
- The strong hydrogen bonds give water its special properties.

These bonds give water:
1. a strong structure and take a lot of energy to break.
2. a great deal of cohesion and surface tension (i.e. trees' water transportation)
3. a high boiling point because it takes a lot of energy to break the bonds (i.e. our body temperature is stable and we can cool ourselves through evaporation)
4. the ability to absorb heat (it is liquid in a range of temperatures)

Also:
1. Ice is less dense than its liquid form and therefore floats on top of water
2. Water dissolves many different things (polar & charged molecules, however NOT nonpolar ones such as hydrocarbon)

Solutions in Water

- Dissolving polar crystals, such as sugar, in water requires water to displace existing covalent bonds with dipole-dipole interactions with itself ➟ some sugar atoms can leave and float freely surrounded by water ➟ this happens more and more and finally the crystal disappears (sugar molecules and water form a solution)
- Solvent = the substance that does the dissolving, i.e. water
- Solute = the molecules that are dissolved, i.e. sugar
- Concentration is measured by molarity (mol/l). A mole is 6 x 10^23 molecules. One mole of one substance has the same number of molecules as a mole of another substance (even if they don't have the same weight). 

Acids and Bases

- Acid = a proton donor
- Base = a proton acceptor
- H+ has only a positively charged proton. HCl his a strong acid. Chlorine atoms form ionic bonds with hydrogen atoms. 

NOT FINISHED YET