On Ramps Chemistry ET: 24

STUDY FOR ONRAMPS CHEMISTRY FR!!!!! FIGHTING!!!

Maxwell Distribution

• A collection of gas molecules undergoes collisions that can speed up or slow down velocity.

• Result is a distribution with average energy ∝ T

• As average T increases, distribution

  spreads to higher velocity

• As mass decreases, the velocities
  spread

Physical Property Distribution

Know the following simple facts about liquid properties

• Evaporation – surface phenomenon in which the IMF of surface

molecules is broken by T to convert liquid to vapor

• Surface tension – surface phenomenon in which molecule IMF

makes molecules assume smallest surface area possible

• Boiling point – T at which molecules in the bulk achieve a vapor

pressure greater than atm pressure and escape

• Capillary action – tendency of surface molecules to adhere to

solid material surrounding the liquid

Assigning types of Solids

There are 4 types of solids:

• Metals – found on left side of periodic table (ex. Na, Fe, Au, Pb)

• Ionic – salts formed by cations from left side of table and anions on

right side of table (ex. NaCl, BaCl2, Al2O3)

• Network covalent – long chain of atom on right side of table (ex.

Wood, plastics, graphite, diamond)

• Molecular solids – small molecules you drew in Unit 2 that form IMF

at low T (ex. Ice, dry ice)

Ranking properties of solids (melting point)

Salts have boiling points that generally scale with charge density (similar to ranking lattice energies)