Honors Chemistry
Mr. Fedell
Chapter 2 Notes – Matter and Change
(Student edition)
Chapter 2 problem set: 37, 41, 46, 49, 54, 60-63, 67
Useful diagrams:
2.1
2.3, 2.8, 2.11
Properties of Matter
Matter: Anything that has
except
and takes up
. It is everything
.
Matter and energy are related in the equation:
Describing Matter: Properties are used to describe matter.
Mass: is a measure of the quantity of
Volume: is a measure of the
.
occupied by the object.
Properties - Characteristics of a substance which help to identify it.
Two questions: What can be observed? How does it behave with other substances?
Identifying Substances:
Substance: matter that has a uniform and definite composition.
Physical Property: a quantity or condition of a substance that can be observed or
measured
the substance’s composition.
States of Matter:
There are 4 phases of matter, but 3 main phases we deal with in chemistry.
solid ( ), liquid ( ), and gas (
)
Phases
Volume
Shape
Solids
__________
_________
Liquids
Fixed
____________ Container
Gases
Equal to Container
Equal to Container
1
2.3
Distinguishing Substances and Mixtures:
The classification of matter chart:
Elements and Compounds (pure substances)
Element: A substance that can not be broken down by ordinary chemical reaction
(extraordinary ).
Compound: When two or more elements are
combined.
Molecule: The smallest particle of a compound that can exist on its own.
usually, molecules are assumed to be compounds, but...
Some elements can exist as atoms, some elements can exist only as molecules….
Monatomic Molecules: an atom, but also a molecule. Examples:
Diatomic Molecules:
Polyatomic Molecules:
Constant Composition: When every
in a substance is exactly the same.
Elements and compounds have constant composition. The word homogeneous can also
be used to describe elements and compounds since every
is the same.
Symbols of the Elements: sometimes, the Latin name is the source of a chemical symbol.
- ferrum
- cuprum
- plumbum
- natrium
- stannum
- aurum
- wolfram originally (German) - now it stands for
some elements are named after
, some after
2
2.2
Mixtures
Mixtures: two or more substance that are
combined, each of which
retains its own
. It can be element-element, compound-compound, etc.
Mixtures are classified based on the distribution of their components.
Homogeneous Mixture (AKA
):
This mixture is transparent and evenly mixed. Salt water is an example of a solution.
Every sample is the same; however, they do not necessarily have constant composition.
Constant composition is where every particle is the same.
Heterogeneous Mixture (AKA
): This mixture shows
(visible, distinct parts of the mixture). It is not evenly mixed. Example: olive garden
salad.
2.3 Continued …
Types of Mechanical Mixtures: suspensions, emulsions, and colloids.
Mechanical mixtures exhibit the
effect. This is the reflection of
light off of particles big enough to reflect light. An example is dust in the
projection light at movie theaters.
A comparison of solutions and mechanical mixtures:
Category
Hetero or
Homo
Particle
Size
Solutions
Colloids
Suspensions
Emulsions
Settling
Tyndall
Effect
Examples
So..how can we tell the difference?...
1. Solution vs. Any M.M. = M.M. show Tyndall effect
2. Colloid vs. Supsension OR Emulsion = Colloids don’t settle
3
It is commonly thought that all solutions are liquid based, but that is not true.
Brass: solid, solid solution
Air: gaseous solution
Aqueous (aq):
2.2 Continued …
Separating Mixtures: differences in physical properties can be used to separate mixtures.
Filtration: The process that separates a solid from a liquid in a heterogeneous mixture.
2.4 Chemical Reactions
Chemical and Physical Properties:
Physical Property: a property that can be observed without changing the
substance into a new substance.
Examples:
Chemical property: a property that can be observed when changing the substance
into a new substance (or properties that describe how a substance
interacts or doesn’t interact with other substances).
Examples: see chemical changes
Chemical and Physical Change:
Chemical Change: a change when the substance turns into another substance by
losing, gaining, or rearranging atoms.
Examples:
A chemical change is a chemical reaction. Reactants are the substances at
the start of the reaction. Products are the substances produced in the reaction.
Physical Change: when a substance changes form, but not its identity or
chemical properties.
Examples:
Physical changes can be classified as reversible or irreversible.
The signs of a chemical change are:
Precipitates:
4