Chem. Lecture 7/21

Solids have…
Solids have definite shape and definite volume
Liquids have….
Liquids have definite volume but variable shape
Gases have…
Gases have indefinite shape and indefinite volume; always fills its container
Solid → Liquid
Solid → Liquid = MELTING
Solid → Gas
Gas → Solid
Gas → Solid = Deposition
Liquid → Gas
Liquid → Gas = Boiling or Vaporization
Gas → Liquid
Gas → Liquid = Condensation
Solid → Gas
Solid → Gas = Sublimation
Define extensive properties

Extensive Properties – depend on how much there is

(i.e mass, volume)

Define Intensive Properties

Intensive Properties – not dependent on amount


(ie. melting pt, solubility, color, etc.)

Difference between

Physical change and Chemical change

Physical change – substance itself doesn’t change


Chemical;change – substance changes into something else (only a single particle/atom needed to determine the chemical property)

Homogeneous Mixtures have….
Homogeneous Mixtures have uniform properties
Atomic mass unit (amu) based on…
Atomic mass unit (amu) based on the mass of C-12/12.
Empirical Formula shows…

Empirical Formula shows the ratio of the elements


An unbalanced equation is also called a…
An unbalanced equation is also called a S K E L E T O N Equation
How is molar mass determined?
Molar mass is the same as atomic mass found on the periodic table
Mass ; Moles

Mass ; Moles


Divide total mass by molar mass to find the number of moles

Particles ; Moles

Particles ; Moles


Divide by 6.022 x 1023 (Avogadro’s #)

Volume (Liters at STP) → Moles

Volume (Liters at STP) → Moles


vol. in liters ÷ 22.4 liters/mol