CHE121 - Unit 1 exam

Deposition

Vapor to solid

Sublimation

Solid to vapor

Why do crystalline solids exist?

Nature loves lower energy states and forming a lattice releases a large amount of energy due to strong ion–ion attractions.

The normal boiling point of a liquid is

the temperature at which the liquid’s vapor pressure equals 760 torr

Freezing point depression

adding a solute (e.g., salt, sugar) to a solvent (e.g., water) lowers its freezing point. Think salt on roads in winter

largest ΔTf =

Lowest freezing point

Increasing the temperature does what to solubility?

Increases!

In metals, at room temperature, the valence band

has no gap separating it from the conduction band

Colligative Properties

physical properties of solutions that depend on the quantity of

solute particles present, not on their identity.

Electrolytes

Electrolytes break apart into charged ions in solution, allowing them to conduct electric current. Non-electrolytes dissolve as neutral molecules, not ions, and therefore do not conduct electricity.

In insulators, the valence band   

is significantly lower in energy than the conduction band