SOLUTIONS

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SOLUTIONS
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Goal

• The students will gain an understanding of
  solutions and other mixtures.

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Concept 1 (p. 41)

• A mixture is made up of two or more substances
  that can be separated by physical means.

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Concept 2 (p. 42 186-90)

• A heterogeneous mixture differs from point to
  point.
• Examples Muddy water and dusty air
• A homogeneous mixture the same throughout.
• Examples Salt water and metal alloys (jewelry)

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Concept 3 (p. 190)

• A solution is a homogeneous mixture of two or
  more substances uniformly spread in a single
  phase.
• Examples Sodas, Prepared Kool-aid, Salt water

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Concept 4 (p. 190)

• A solution consists of (2) parts
• The solute usually occurs in the smaller amount
  and is dissolved into the solvent.
• The solvent usually occurs in the larger amount.

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Concept 5 (p. 192-94)

• Solutions form when
• particles of the solute spread out evenly in the
  solvent
• the attraction between the solute particles and
  solvent particles is greater than the attraction
  between solute particles alone.

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Concept 5 (cont.)

• Solutions can consist of any combination of the
  three phases of matter.
• Examples metal alloys, vinegar, carbonated
  drinks, and diving air

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Concept 6 (p. 194-95)

• Water is described as the universal solvent
  because more substances will dissolve in water
  than any other known solvent.

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Concept 7

• The five physical properties of solutions are
• Homogeneous
• Liquid solutions appear clear or transparent
• Proportions may vary
• The solute will not settle from the solvent
• The solute cannot be filtered from the solvent

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Concept 8 (p. 193-94)

• The rate of solution depends on several factors
• Particle size
• Example Crushing a sugar cube will help dissolve
  it faster
• Stirring or shaking the mixture increases the
  rate of solution
• Temperature

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Concept 9 (p. 194, 197)

• Solubility is the amount of solute that can be
  dissolved in a given solvent

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Concept 10 (p. 193,194,196)

• The three factors affecting solubility are
• Temperature
• Increasing the temperature will increase the
  solubility of a SOLID solute, BUT will decrease
  the solubility of a GAS solute in a solution.)
• Examples Sugar dissolves best in warm tea
  there is more oxygen for fish in cool water.

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Concept 10 (cont.)

• Pressure
• If pressure is increased, more solute will stay
  in solution
• Example Sodas lose their bubbles when the can is
  opened

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Concept 10 (cont.)

• Nature of the solvent and solute
• Organic solvents dissolve organic solutes.
• Inorganic solvents dissolve inorganic solutes.
  Water is an exception.

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Concept 11

• A solubility curve is a graph showing how much
  solute is dissolved in a solvent over a range of
  temperatures.

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Concept 12 (p. 196-97)

• An unsaturated solution can dissolve more solute
  in it.
• A saturated solution at a given temperature will
  not dissolve any more solute.
• A supersaturated solution contains more solute
  than a saturated one has at that temperature.

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Concept 13

• The addition of solute particles raises the
  boiling point of a solution.
• The addition of solute particles lowers the
  freezing point of a solution.

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Concept 14 (p. 48,190)

• The physical methods of separating mixtures are
  
• Evaporation is removing water from a solution or
  removing the liquid portion from a mixture
  without adding heat.
• Distillation is the separation of two liquids
  because of a difference in boiling points.

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Concept 14 (cont.)

• Filtration is the removal of an insoluble solid
  from a liquid mixture.
• Filtrate is the portion of the filtered mixture
  which passes through the filter.

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Concept 15 (p. 186-87)

• A colloid is a mixture of very tiny particles of
  pure substances that are dispersed in another
  substance but do not settle out of a substance.
• Examples Milk, Fog, Smoke, Jelly, Mayonnaise,
  Whipped Cream

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Concept 15 (cont.)

• A suspension is a mixture that looks uniform when
  stirred or shaken that separates into different
  layers when it is no longer agitated
• Examples Salad Oil, Paint, Muddy water

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Concept 16 (p. 186-88)

• The characteristics of solutions, colloids
  suspensions