Chemistry of Water Chapters 8 + 15 + 16. What Makes Water So Special? Polarity- waters bent shape...

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Chemistry of Water Chapters 8 + 15 + 16

Transcript of Chemistry of Water Chapters 8 + 15 + 16. What Makes Water So Special? Polarity- waters bent shape...

Page 1: Chemistry of Water Chapters 8 + 15 + 16. What Makes Water So Special? Polarity- waters bent shape creates δ- and δ+ areas in the molecule.

Chemistry of WaterChapters 8 + 15 + 16

Page 2: Chemistry of Water Chapters 8 + 15 + 16. What Makes Water So Special? Polarity- waters bent shape creates δ- and δ+ areas in the molecule.

What Makes Water So Special?

Polarity- water’s bent shape creates δ- and δ+ areas in the molecule

Page 3: Chemistry of Water Chapters 8 + 15 + 16. What Makes Water So Special? Polarity- waters 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

Page 4: Chemistry of Water Chapters 8 + 15 + 16. What Makes Water So Special? Polarity- waters bent shape creates δ- and δ+ areas in the molecule.

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

Page 5: Chemistry of Water Chapters 8 + 15 + 16. What Makes Water So Special? Polarity- waters bent shape creates δ- and δ+ areas in the molecule.

Intermolecular Forces Dipole interactions- van der Waals

forces seen in polar molecules as a result of partial charge distribution

Page 6: Chemistry of Water Chapters 8 + 15 + 16. What Makes Water So Special? Polarity- waters bent shape creates δ- and δ+ areas in the molecule.

Intermolecular Forces dispersion forces- weakest van der

Waals force caused by motion of electrons and increase as # of electrons increases

Page 7: Chemistry of Water Chapters 8 + 15 + 16. What Makes Water So Special? Polarity- waters bent shape creates δ- and δ+ areas in the molecule.

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)

Page 8: Chemistry of Water Chapters 8 + 15 + 16. What Makes Water So Special? Polarity- waters bent shape creates δ- and δ+ areas in the molecule.

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

Page 9: Chemistry of Water Chapters 8 + 15 + 16. What Makes Water So Special? Polarity- waters bent shape creates δ- and δ+ areas in the molecule.

Properties of Water Density of Ice-

decreases from 4 to 0°C because molecules become “locked” in place as kinetic energy is decreased

Page 10: Chemistry of Water Chapters 8 + 15 + 16. What Makes Water So Special? Polarity- waters bent shape creates δ- and δ+ areas in the molecule.

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)

Page 11: Chemistry of Water Chapters 8 + 15 + 16. What Makes Water So Special? Polarity- waters bent shape creates δ- and δ+ areas in the molecule.

Electrolytes all ionic compounds and some highly polar covalent

compounds that can complete an electrical circuit

Page 12: Chemistry of Water Chapters 8 + 15 + 16. What Makes Water So Special? Polarity- waters bent shape creates δ- and δ+ areas in the molecule.

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

Page 13: Chemistry of Water Chapters 8 + 15 + 16. What Makes Water So Special? Polarity- waters bent shape creates δ- and δ+ areas in the molecule.

Remember? Solutions,

Suspensions, and Colloids...

Page 14: Chemistry of Water Chapters 8 + 15 + 16. What Makes Water So Special? Polarity- waters bent shape creates δ- and δ+ areas in the molecule.

Properties of Solutions

rate of dissolving is determined by: agitation, temperature, and particle size

Solutions may be unsaturated, saturated, or supersaturated

“like dissolves like”