Physical Properties of Matter

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Physical Properties of Matter
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• You live in a huge universe of matter. Because
  you cannot live without a sense of order. Our
  sorting techniques are usually based upon what we
  can detect with our senses. The characteristics
  of substances we can note with our physical
  senses are physical properties. Just as you can
  recognize your friends by their physical
  appearance, you can also recognize matter by its
  physical appearance and properties.

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• Physical Properties
• a property that can be determined without
  changing the composition of the substance
• Examples color, odor, density, melting point,
  boiling point

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• We have studied how to find the density of
  matter.
• As you know, the equation for density is
• density mass (grams)
• volume (mL or cm3)
• mass density x volume
• volume mass
• density

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• The following is a list of other ways of telling
  one form of matter from another.
• ductility The property displayed by certain
  metals that enables them to be drawn out into
  wires without breaking
• malleability The property displayed by certain
  metals that enables them to be hammered, rolled
  out, shaped, etc. without breaking

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• hardness The property of an object that resists
  being crushed or deformed
• brittleness The property of an object that can
  easily be broken or crushed into smaller pieces
  under low pressure
• conductivity The property of metals, some
  metalloids, and ionic solutions that allow an
  electric current to pass through them
• state or phase form gas, liquid, solid in
  which matter is found

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• solubility The property of a substance that
  allows it to dissolve
• melting point The temperature at which a solid
  changes to a liquid
• boiling point The temperature at which a liquid
  changes to a gas

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The Separation of Matter

• If you were to begin your study of chemistry by
  looking at substances handy to you, you would
  most likely encounter more mixtures than anything
  else. In this section, we will discuss several
  methods for separating mixtures. As you read
  about each technique, see how many uses you can
  identify for it. These are the methods in which
  you will need to be familiar to do the activities
  later in this course

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• Method 1 Filtration
• is a process of separating large solid particles
  from a liquid by passing the components through a
  porous material like filter paper.
• Filtrate The liquid that passes through the
  porous medium
• Residue the solid material that does not pass
  through the porous medium

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Example

• In everyday use, substances are usually filtered
  to remove undesirable particles. One familiar
  example of filtration is the purification of
  water in a swimming pool. This is done by
  continuously pumping water through the pool's
  filter. As the water passes through the filters,
  dirt and any other types of debris that might be
  harmful are removed. Another example is the
  filtration of air in heated and air-conditioned
  buildings. The air is filtered either by a
  filter on the furnace or in the air intake system
  in a building in order to cleanse the air
  impurities.

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• Method 2 Crystallization
• is a process in which crystals are formed by
  removing the liquid part by evaporation (change
  from liquid to gas without adding heat) or
  vaporizing (change from liquid to gas with adding
  heat)

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Example

• Salts can be purified by dissolving them in
  water, filtering the solutions, and then
  crystallization. The liquid part of the solution
  is evaporated or heated off and the solid part
  (salt) remains. Salt has been collected from the
  worlds oceans for thousands of years using this
  technique.

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REMEMBER TO BRING A WHITE T-SHIRT FOR WEDNESDAY
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• Distillation is another important technique used
  to separate both solid/liquid mixtures and
  liquid/liquid mixtures. In simple distillation
  of a solid/liquid mixture, the liquid is removed
  from the mixture by evaporation and then
  recollected by condensation.

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• However, when you have a liquid/liquid mixture,
  the mixture must be separated by a more
  complicated technique called fractional
  distillation. When the mixture of liquids is
  heated, the liquid with the lowest boiling point
  is distilled first. This liquid turns into a
  vapor (gas) and flows out the distillation flask.
  As it enters the condensing tube, it is cooled
  and condenses back into a liquid. It is then
  collected in a graduated cylinder. When the
  liquid is almost completely evaporated the liquid
  with the next lowest boiling point begins to
  distill. This process continues until there is
  nothing, or only solid impurities, left in the
  distillation flask.

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• Method 3 Distillation
• is a process of separating a mixture based on
  different boiling points
• Vaporization a change from liquid to gas at the
  boiling point when heat is added
• Condensation a change from gas to liquid at the
  condensation point when heat is removed.
• Fraction each different liquid that is
  separated out of the mixture

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• You probably have watched an ink drawing dissolve
  into a rainbow of colors when water has fallen on
  it. When an ink drawing comes into contact with
  water, the water will drag the inkspot with it as
  it moves across the paper. Some substances in
  the ink move more slowly than others. We can
  apply this property to separate the components of
  the mixture. The result is that the ink
  separates into different colors.

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• Method 4 Chromatography
• a technique used to separate and analyze various
  substances in a mixture. The separation occurs
  because the components are not equally soluble in
  a solvent and the components are not equal in
  size.

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Chemical Properties of Matter

• Chemical Properties
• A property of a substance that is observed when
  the substance undergoes a change in composition
• active reacts vigorously with other materials
• inactive does not react readily with other
  materials
• inert do not react under normal or ordinary
  conditions

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Changes in Matter

• Now that we have learned the fine points about
  physical and chemical properties, we are going to
  look at two kinds of changes physical changes
  and chemical changes.

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• Physical Changes
• refers to a change in appearance not chemical
  composition of the substance
• Examples phase changes (s-gt l -gt g), crushing,
  grinding, dissolving (solubility)

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• Is tearing a piece of paper a physical change?
• YES
• Why or why not?
• the composition of the matter does not change.
  It is a change in appearance only.

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• Is solid water (ice) changing into liquid water a
  physical change?
• YES
• Why or why not?
• the composition of the matter does not change.
  It is a change in appearance only.

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• Chemical Changes
• refers to a change in the composition of the
  matter......a new substance is formed
• Examples rusting of iron , combustion of a
  candle, burning of gasoline to run a car

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• There are some key signs that you can look for to
  determine whether or not a chemical change has
  occurred. These are as follows

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• 1. A gas is given off (BUBBLES) but not
  boiling
• 2. A precipitate (insoluble solid) is
  produced..... appears cloudy
• 3. Water is produced ..... Cobalt chloride paper
  turns from blue to pink
• 4. A color change could indicate a chemical
  change but also may indicate only a physical one
• 5. A temperature change may indicate a chemical
  change but can also indicate a physical one