Chemistry

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CHAPTER 1 2

• Chemistry
• Matter Change

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CHEMISTRY
STUDY OF COMPOSITION AND BEHAVIOR OF MATTER
What stuff is made of and how it acts
Organic Chemistry
Study of carbon compounds
Inorganic Chemistry
Study of non carbon compounds
Analytical Chemistry
Study of composition of substances
Physical Chemistry
Study of behavior of substances
Biochemistry
Study of the chemistry of living things
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How Chemistry is Used

• Pure Chemistry
• Knowledge for knowledges sake. Research to
  learn how something works. May lead to and
  application.
• Ex Research for synthetic rubber 1940s
• Applied Chemistry
• Research directed to a specific goal or
  application.
• Ex Silly Putty 1950s

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Scientific Method

• Systematic problem solving approach
• Observations
• Noticing a problem (car wont start)
• Hypothesis (battery dead)
• Possible explanation
• Experiment
• Procedure used to test the hypothesis (jump
  start?)
• Manipulated Variable Independent Variable
• Variable you change during an experiment.
• Responding Variable- Dependent Variable
• Variable you observe during the experiment

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Scientific Method Continued
Tested model that explains WHY an experiment
gives certain results.
THEORY
Ex Atomic Theory
Model of atom has changed over time.
Statement that summarizes the results of many
observations and experiments. Can be proven and
usually is an equation.
LAW
Ex Law of Gravity (objects fall at a rate of
9.8 meters per second)
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PROPERTIES OF MATTER
MATTER
Anything that has mass and takes up space
MASS
Amount of substance and object contains
WEIGHT
Earths attraction for an object
GRAVITY
VOLUME
Amount of space an object takes up
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PHYSICAL PROPERTY

• QUALITY OF A SUBSTANCE that can be analyzed
• without changing the composition of the
  substance,

Ex color, odor, density, MP, BP, conductivity
CHEMICAL PROPERTY

• ability of a substance to undergo a chemical
  reaction and form new substances

Ex sodium explodes in water, iron nail rusts,
wood burns
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Changes in Matter
Change in a substance that does not change
composition. Same substance in the beginning and
end.
Physical Change
Ex cutting, grinding, tearing, painting, phase
change
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Chemical Change

• Change in the composition of a substance.
  Different substance in the end.
• Ex burning, rusting, chemical reactions

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Demo SUGAR WATER
REACTANTS YIELD PRODUCTS
C12H22O11 H2O ? C12H22O11
H2O
STARTING AND ENDING MATERIALS ARE THE SAME
PHYSICAL CHANGE
DEMO SUGAR SULFURIC ACID
REACTANTS YIELD PRODUCTS
C12H22O11 H2SO4 ? 12 C SO3 12 H2O
STARTING AND ENDING MATERIALS ARE
DIFFERENT CHEMICAL CHANGE
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INDICATORS OF A CHEMICAL CHANGE
COLOR CHANGE
ODOR CHANGE
ENERGY CHANGE
FORMATION OF A GAS
FORMATION OF A PRECIPITATE- (solid formed from 2
aqueous solutions)
NOT EASILY REVERSED
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Whats happening during a chemical reaction?
Only the OUTER SHELL ELECTRONS called (Valence
Electrons) of atoms are involved.
atoms
Combine, break away or rearrange
Law of Conservation of Mass
Matter is not created or destroyed.
Mass reactants Mass of products
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Energy Changes
Both physical and chemical changes involve energy
changes
Types of energy include heat, light, bond energy
Needs or requires energy (heat), takes heat in,
surroundings feel cooler
ENDOTHERMIC
Energy is a (REACTANT)
Gives off or releases energy (heat), gives off
heat, feels warmer.
EXOTHERMIC
Energy is a (PRODUCT)
Law of Conservation of Energy
Energy is not created or destroyed.
Energy of reactants Energy of products
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States of Matter
Density Movement shape
volume D mass/volume
Packed very close together, incompressible
Vibrate in place
solid
definite
definite
Packed close together, incompressible
Slide past each other
definite
indefinite
liquid
Very far apart (99empty space), compressible
Rapid, random straight line
gas
indefinite
indefinite
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Phase Changes
HEAT IN (ENDOTHERMIC)
MELTING
BOILING
SOLID ?? LIQUID ?? GAS
HEAT OUT (EXOTHERMIC)
FREEZING
CONDENSATION
H2O ICE WATER
WATER VAPOR
The term VAPOR is used when a substance that is
normally a liquid or solid at room temperature is
in a gaseous state.
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Types of Matter

• Substance Mixture
• (homogeneous)
• (_________________________) (_______________
  _______)
• 
  (______________________)
• Element Compound
  Homogeneous
  Heterogeneous
• (_______________________)
• Element _____________________
  Homogeneous (______________________)
• ______________________________ __________________
  ___________
• Compound ____________________
  Heterogeneous _________________
• ______________________________
  _____________________________
• (_____________________________)
  _____________________________

Definite composition
Variable composition
Separated physically
Separated chemically
One kind of atom
solution one phase
Found on periodic table, H, He
Same throughout koolaid, jello
Chemical blend
Not the same
of 2 or more elements
throughout different phases
H2O, NaCl, BaSO4
Chunky soup, salad, soil
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Comparison of Compound VS Mixture
Compound Mixture
1. Chemically combined Physically combined

• Can only be separated by Can be separated
• chemical means. physically.

• Components are present in a Components may be
• definite proportion by weight present in
  any proportion

• Compound has different Components in
  mixture
• properties than its individual keep their
  original
• components. properties.

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Chemical Symbols
- Every element has a symbol - Symbol consists of
1 or 2 letters, first is capitalized

• Some named for Greek and Latin names

- Ex Sodium (Natrium) Na Iron (Ferrous) Fe
-Chemical Formulas
Combination of elements to represent compounds.
Ex C12H22O11 sugar H2O water
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Reaction symbols
(s)
(l)

• solid

• liquid

The following are the only liquids used during
a chemical reaction
Water, Bromine Mercury
Everything else in a liquid state is an
Aqueous Solution
(g)

• gas

( )

• gas as a product

Solid product formed from 2 aqueous solutions

• precipitate

( ) or (ppt.)

• aqueous

(aq)
Dissolved in water.