Upload
zoe-hansen
View
223
Download
1
Embed Size (px)
Citation preview
Chemistry of WaterChapters 8 + 15 + 16
What Makes Water So Special?
Polarity- water’s bent shape creates δ- and δ+ areas in the molecule
Intermolecular Forces forces of attraction that
occur between molecules of a substance
Hydrogen Bonds Van Der Walls Forces
Dipole-Dipole Interactions
Dispersion Forces
Intermolecular Forces1. Hydrogen Bonding- strongest intermolecular force,
2. 5% of covalent bond.
3. hydrogen is bonded to a strongly electronegative atom (O, N, F) and is also attracted to lone electron pairs on a neighboring molecule
Intermolecular Forces Dipole interactions- van der Waals
forces seen in polar molecules as a result of partial charge distribution
Intermolecular Forces dispersion forces- weakest van der
Waals force caused by motion of electrons and increase as # of electrons increases
Properties of Water Surface Tension- water
has an unusually high surface tension because its molecules are strongly attracted to one another (as opposed to their attraction to air molecules)
Properties of Water Heat Capacity- we are able to inhabit
this planet because it takes a lot of energy to raise the temperature of water
Properties of Water Density of Ice-
decreases from 4 to 0°C because molecules become “locked” in place as kinetic energy is decreased
Water as a Solvent Ionic and Polar Compounds- tend to
become solvated in water to form aqueous solutions…
why?
(Note: some ionic compounds are too strongly attracted to be soluble in water)
Electrolytes all ionic compounds and some highly polar covalent
compounds that can complete an electrical circuit
Types of Electrolytes Strong Electrolytes- inorganic acids, inorganic
bases, and ionic compounds that are completely soluble
Weak Electrolytes- organic acids, organic bases, ionic compounds that are slightly soluble, and highly polar molecules
Nonelectrolytes- nonpolar and organic compounds
Remember? Solutions,
Suspensions, and Colloids...
Properties of Solutions
rate of dissolving is determined by: agitation, temperature, and particle size
Solutions may be unsaturated, saturated, or supersaturated
“like dissolves like”