View
230
Download
0
Category
Tags:
Preview:
Citation preview
Chapter 1/2Chemistry and Matter
What is Chemistry?
Chemistry is the study of matter and the changes that matter undergoes.
Because all things are made up of matter, chemistry affects all aspects of life.
Areas of Chemistry
Organic Chemistry
Inorganic Chemistry
Biochemistry
Analytical Chemistry
Physical Chemistry
The Scientific Method
Making Observation (leads to a question)
Developing a Hypothesis
Experiment (Test Hypothesis)
Conclusion (Develop Theory or Scientific Law)
Repeat experiment
Matter
Matter: Anything that takes up space and has mass (inertia)Mass: The measure of the amount of matter that an
object containsProperties of Matter: Describes the characteristics
and behavior of matter, including the changes that matter undergoes
Matter
The Macroscopic View of MatterMatter that is large enough to be seen
The Submicroscopic View of MatterSo small that you cannot see it, even
with the most powerful microscope
The Microscopic View of MatterSmall enough that a microscope is
needed.
Extensive vs. Intensive
An extensive property is a property that depends on the amount of matter in a sample.Ex. Mass, volume, length, etc.
An intensive property is a property that depends on the type of matter in a sample, not the amount of matter.Ex. Color, Texture, density, etc.
Observations of matter
Qualitative: made without measurementEx. Color, texture, shape, etc.
Quantitative: made with measurementEx. Mass, volume, length, etc.
States of Matter
Solid: a form of matter with definite shape and volume
Liquid: a form of matter with a indefinite shape, but a definite volume
Gas: a form of matter with an indefinite shape and volume
SOLID LIQUID GASFreezing
Evaporation
Melting
Sublimation
Condensation
MixturesMixture: A combination of two or more
substances in which the basic identity of each substance is not changed.
Mixtures can be classified as heterogeneous or homogeneous
Heterogeneous Mixtures: A mixture that has a composition that is different throughout.Ex. Cookie Dough ice cream
Homogeneous Mixtures: A mixture that has a composition that is the same throughout.Ex. Lemonade (solutions)
Solutions
A solution is made up of a solute and a solvent
Solute: The substance being dissolved
Solvent: The substance doing the dissolving
When the solvent is water the solution is said to be ‘AQUEOUS” (an aqueous solution.)
SOLUTE + SOLVENT = SOLUTION
SUGAR + WATER = AQUEOUS SUGAR
SOLUTION
Separating MixturesDifferences in Physical
properties can be used to separate mixtures.
Filtration: a process that separates a solid from a liquid in a heterogeneous solution.
Distillation: A liquid is boiled to produce a vapor which is then condensed into a liquid (used to separate a liquid from solids or to separate two liquids)
Elements vs. Compounds
Element: simplest form of matter that has a unique set of properties.
Compound: substance that contains two or more elements chemically combined
Compounds can be broken down into simpler substances by chemical means, elements cannot.
Symbols
Chemists use chemical symbols to represent elements, and chemical formulas to represent compoundsEx. Sodium = Na, Chlorine = Cl Ex. Sodium Chloride = NaCl
MATTER
Matter
MIXTURES PURE SUBSTANCES
COMPOUNDSHOMOGENEOUSMIXTURES ELEMENTSHETEROGENEOUS
MIXTURES
PHYSICAL CHANGES
DIRT, BLOOD, MILKSODA, GASOLINE,
AIR
SALT, BAKING SODA,SUGAR
OXYGEN, GOLD,IRON
Density
The amount of matter (mass) contained in a unit volume.
DENSITY =
MASS per VOLUME
-OR-
GRAMS PER MILLILITER
VOLUME
Measured in grams
Measured in milliliters
DENSITY =
MASS
Chemical vs. Physical Changes
Physical Property: a quality or condition of a substance that can be observed or measured without changing the substance’s composition Ex. Solubility, melting point, boiling point,
color, density, electrical conductivity, and physical state (solid, liquid, gas)
During a physical change, the composition of matter always remains the same. Tearing, cutting, grinding Change of state: boil, freeze, melt, and
condense
Chemical vs. Physical Changes
Chemical Property: the ability of a substance to undergo a chemical change is called a chemical property Ex. Flammable, corrosive, ability to rust
During a chemical change, the composition of matter always changes Ex.. burn, rot, rust, decompose, ferment,
explode, corrode A chemical change is also called a chemical
reaction. Possible indicators of a chemical change
include: a transfer of energy a change in color the production of gas or the formation of a precipitate
Chemical Reactions and Energy
Energy the capacity to do work
All chemical changes involve some sort of energy change.
Energy is either given off ….“EXOTHERMIC”
Or….taken in…. “ENDOTHERMIC”
Law of Conservation of Mass and EnergyThe law of
conservation of mass and energy states that both matter and energy cannot be created or destroyed in any process
IT’S THE LAW!!!
Energy
Energy is the capacity to do work or produce heat
Kinetic Energy: Energy of Motion
Potential Energy: Energy of Position (stored energy)
Recommended