Chemistry 112Chapter Two: Matter and Change

Properties of MatterIf you had to describe matter, what would you

say?

Describing MatterPROPERTIES USED TO DESCRIBE MATTER CAN BE

CLASSIFIED AS EXTENSIVE OR INTENSIVEExtensive properties include:

The mass of the objectThe volume of the objectIt depends on the amount of matter in a sample

Intensive properties include:HardnessSmoothnessDepends on the type of matter in a sampleEx. All samples of pure gold have identical intensive

properties because their chemical composition is identical.

Identifying SubstancesMatter that has uniform and definite

composition is called a substanceEVERY SAMPLE OF A GIVEN SUBSTANCE

HAS IDENTICAL INTENSIVE PROPERTIES BECAUSE EVERY SAMPLE HAS THE SAME COMPOSITION

Examples of physical properties include:Hardness, boiling point, freezing point,

colour, conductivity, malleabilityPhysical properties can be observed and

measured without changing the substance's composition

Copper vs. GoldHow are they different/same?

Page 40, Table 2.1

States of MatterTHREE STATES OF MATTER ARE SOLIDS,

LIQUIDS AND GASESSolids have definite shape, volume and not

easily compressedLiquids have indefinite shape, definite

volume and not easily compressedGases have indefinite shape, indefinite

volume, and are easily compressedThe particles composing each varies from

state to state

See Figure 2.3 on page 41

Physical ChangesDuring a physical change, some properties of

the material changes, but the composition does not

What are some words that could be used to describe physical changes of a substance?

Look at Figure 2.4, and answer the questions – Is the melting of gallium a reversible or irreversible change? What is the physical state of gallium at room temperature?

MixturesA mixture is a physical blend of two or more

componentsBASED ON THE DISTRIBUTION OF THEIR

COMPONENTS, MIXTURES CAN BE CLASSIFIED AS HETEROGENEOUS MIXTURES OR AS HOMOGENEOUS MIXTURES

Heterogeneous mixtures do not have uniform composition (trail mix). Each part is called a phase.

Homogeneous mixtures, or solutions, have uniform composition (stainless steel). By definition, they have one phase.

Separating MatterDIFFERENCES IN PHYSICAL PROPERTIES

CAN BE USED TO SEPARATE MIXTURES

Floating, freezing, filtration, distillation, using magnets, etc.

Check for comprehension:Questions 1 -8, pg. 42Questions 9-10, pg. 46

Questions 11 – 17, pg. 47Guided reading, sections 2.1, 2.2