Properties of Matter & KMT

Physical vs Chemical Changes

Physical:

A change that alters a
substance without changing
its composition

Ex) freezing, boiling, and
melting

Chemical:

A change in which one or
more substances turns into
a new substance

Ex) decomposing, rusting,
and burning

Physical Property

A characteristic that can be observed or measured without
changing the samples composition.

Chemical Property

The ability of a substance to combine with or change into
one or more other substances

Ex) Iron forming rust

Copper turning green in air

Physical Properties of Matter

Intrusive

Dependent on what the
substance is and not how
much of it you have

ex) Density

Extrusive

Dependent on how much of
a substance is present

ex) mass, length, and
volume

Law of Conservation of Mass

Mass is neither created nor destroyed in a chemical
reaction, it is conserved

Mass of Reactants = Mass of Products

Phase changes that require energy

Intermolecular Forces (3 types)

Attractive forces between molecules that causes some
materials to be solid, liquid, or gases at the same
temperature

Dispersion Forces

Weak forces that result from temporary shifts in density of
electrons in electron clouds

Dipole- Dipole Forces

Attractions between oppositely charged regions of polar
molecules

Hydrogen Bonds

A special type of dipole dipole attractions that occur
between molecules that contain hydrogen atom bonded to
a small, highly electronegative atom, with at least one lone
pair of electrons.

Usually oxygen, fluorine, or nitrogen

Matter

Anything that has mass and takes up space

3 main types of matter:

Solid, Liquid, and gas

4th: Plasma

Solids and Liquids

Have their own shape

Have a definite volume and
shape

Definite volume

Take the shape of the
container

Gases

Have no defined shape or volume

They expand to fill the container

Standard Conditions for a gas 273K and 101.3kpa

Vapor- refers to gaseous state of a substance that is a solid or liquid
at room temperature

Ex) Water

Kinetic Theory of Gases

Theory that explains properties of a gas, it assumes

a)

Gas particles are small particles separated by empty space

b)

Gas particles are in constant, random, rapid motion with no attractions
or repulsions between particles

c)

Collision are elastic (no kinetic energy lost, just transferred) and creates
pressure

Heat

Heat- is the transfer of energy from an object of higher temperature to an
object of lower temperature

Kinetic energy and temperature are directly proportional (one goes up so
does the other)

Temperature unit is Kelvin (K)

At a temperature of absolute zero (0K), particle movement ceases