CHEMISTRY

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CHEMISTRY -

• the study of the structure and composition of
  matter, the physical and chemical changes it
  undergoes and the energy that is exchanged.

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• structure is the order in which the atoms are
  actually hooked together and how they bond
• composition is what kinds of elements actually
  make-up something
• Matter is the physical "stuff" of the universe.
  It is defined as anything which has mass and
  occupies space.
• Law of Conservation of Matter Matter can neither
  be created nor destroyed only changed by physical
  or chemical means.

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Homogeneous Matter homogeneous means that it is
one phase throughout completely uniform ex
water

• ELEMENT - matter composed of only one type of
  atom the simplest form of matter cannot be
  changed to another element except by a NUCLEAR
  reaction
• 112 have been discovered but only 109 have been
  named and their names accepted only 88 elements
  are naturally occurring all others are man made
• the symbol for an element is 1 capital letter OR
  1 capital letter and 1 lower-case letter.
• Some elements are named by their English
• names the element Carbon is symbolized by its
• English name Carbon C
• Some are named by their Latin names
• Ex The element Sodium is symbolized
• by its Latin name Natrium Na

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Homogeneous matter

• COMPOUNDS are substances composed of more than
  one atom chemically joined together
• compounds can be changed to other compounds and
  separated by chemical reactions only cannot be
  physically separated.
• compounds do not have the same properties of the
  elements which make them up. EX H2O
• the chemical formula for a compound will have
  more than 1 capital letter in it because it
  contains more than one element, Ex C12H22O22
• the proportions of elements in a compound do not
  change or you have changed the compound. For
  example H2O vs H2O2

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Homogeneous Solutions

• SOLUTIONS are a uniform mix of two or more
  substances which are NOT chemically bonded and
  therefore, unlike compounds, each component
  retains its original identity and properties, you
  cannot see the particles of these two substances
  and thus a solution allows the transmittance of
  light.
• A solution has TWO parts--
• SOLUTE is the component which whose phase is
  changed. ONLY if both components are the same
  phase, the solute is the one in the LESSER
  quantity For example Sugar and water
• SOLVENT is the component which remains unchanged.
  
• ONLY if both components are the same phase, the
  solvent
• is the one in the GREATER quantity.
• When two liquids are mixed, we describe their
  interaction as
• MISCIBLE If they dissolve in each other
  completely and
• mix uniformly in any proportions An example of
  miscible
• liquids is vinegar and water.
• IMMISCIBLE If the two liquids do not dissolve in
  each other
• and form two distinct layers, they are said to
  be Examples of immiscible liquids are oil and
  water.
• Alloy When two metals are melted together, like
  gold and silver to make jewelry

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Gold Alloys

• Percentage by WeightThe following table shows
  typical "recipes" for different common gold
  alloys.

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Example practice

• Example 2-1
• Aluminum chloride is a white crystal. Alcohol is
  a clear liquid. When these are mixed, a clear
  liquid solution results. What is the solvent?
• If there is 91 gold , 7 silver and 3 copper
  in 22 kt gold, an alloy. What is the solvent?
  What are the solutes?

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Heterogeneous Matter HETEROGENEOUS SUBSTANCES
ARE ALWAYS MIXTURES! They are not uniform in
composition. There is more than one phase
present

• Dry Heterogeneous Mixtures made of dry
  particles of different types can be elements
  and/or compounds.
• If a solution has particles in it, it is not
  technically called a solution anymore. There are
  two ways we name these types of heterogeneous
  mixtures
• Colloid a mixture whos particles are
• evenly distributed and bigger than the
• particles in a solution but smaller than
• the particles in a suspension
• Suspension a mixture whos particles are so
  large that they settle out unless constantly
  agitated.

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Practice TO CLASSIFY MATTER, YOU MUST ALWAYS USE
TWO WORDS--HOMOGENEOUS ELEMENT, HOMOGENEOUS
COMPOUND, HOMOGENEOUS SOLUTION OR HETEROGENEOUS
MIXTURE.

• Vinegar (acetic acid diluted in water)
• birdseed
• cooking oil
• mouthwash
• ketchup
• water
• silver
• mayonnaise