Solutions Unit

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Solutions Unit
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Obj 1 A pure substance is either an element or
a compound. A mixture is made of two or more
substances that can be separated by physical
means.
Physical means evaporation, chopping, sorting,
filtering, melting anything that does NOT change
the identity of any materials
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Obj 2 heterogeneous mixture differs from
point to point. Ex fruit salad
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Obj 2 heterogeneous mixture
differs from point to point. homogeneous mixture
the same throughout.
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Obj 3 A solution is a homogeneous mixture of 2
or more substances.
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Obj 4. A solution consists of (2) parts
Solute - usually occurs in the smaller amount and
is dissolved into the solvent of a solution
.Solvent - usually occurs in the larger amount.
Solid Solute
Liquid Solute
Gas Solute
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An alloy is a solution of metals. Which
material is the solvent in these examples of gold
alloys?
Copper or Gold?
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FYI / Other Alloys Bronze copper tin Brass
copper zinc Sterling silver silver
copper Pewter tin,copper, antimony Solder
lead, tin Wrought iron iron, lead, copper,
magnesium
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Obj 5 Solutions form when a. particles of
solute spread out evenly in the solvent.
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Obj 5 Solutions form when a. particles of
solute spread out evenly in the solvent. b.
the attraction between solute and solvent
particles is greater than the attraction between
solute particles alone. (EX Kool-aid and water
).
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Solutions can be of any combination of the three
phases. (Ex alloys, vinegar, carbonated drinks,
the air we breathe.)
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Obj 6 Water is described as the universal
solvent because more substances will dissolve in
water than any other known solvent.
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Obj 7The five physical properties of solutions
area. It is homogeneous.b. c. d. e.
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Obj 7The five physical properties of solutions
area. It is homogeneous.b. Liquid solutions
appear clear or transparent.c. d. e.
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Obj 7The five physical properties of solutions
area. It is homogeneous.b. Liquid solutions
appear clear or transparent.c. Proportions may
vary. a few grains of sugar or a tablespoon of
sugar to a liter of water still makes a
solutiond. e.
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Obj 7The five physical properties of solutions
area. It is homogeneous.b. Liquid solutions
appear clear or transparent.c. Proportions may
vary.d. The solute will not settle from the
solvent.e.
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Obj 7The five physical properties of solutions
area. It is homogeneous.b. Liquid solutions
appear clear or transparent.c. Proportions may
vary.d. The solute will not settle from the
solvent.e. The solute cannot be filtered from
the solvent.
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Suspension- a heterogeneous mixture which
may look cloudy, have materials which may settle
or can be separated using a filter.
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The rate of solution depends on several
factorsa. Particle size (EX Crushing a sugar
cube will dissolve it faster).
Obj 8
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The rate of solution depends on several
factorsa. Particle size b. Stirring or shaking
the mixture increases the rate of solution.
Obj 8
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The rate of solution depends on several
factorsa. Particle size b. Stirring or shaking
the mixture increases the rate of solution.c.
Temperature
Obj 8
What is the problem with trying to stir sugar
into ice cold tea?
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The rate of solution depends on several
factorsa. Particle size b. Stirring or shaking
the mixture increases the rate of solution.c.
Temperature
Obj 8
Would the salt dissolve faster in cold or hot
soup?
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The rate of solution depends on several
factorsa. Particle size b. Stirring or shaking
the mixture increases the rate of solution.c.
Temperature- solids dissolve best in warm
solvents Gases dissolve best in cold solvents
Obj 8
Close up on the next slide
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Room Temperature
COLD
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Obj 9 Solubility is the amount of solute that
can be dissolved in a given solvent.
The extra solute settles to the bottom.
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Obj 10 . The three factors affecting
solubilitya. temperature (Increasing the
temperature will increase the solubility of a
SOLID solute, BUT will decrease the solubility of
a GAS solute in a solution.)Ex. Sugar dissolves
best in warm tea. There is more oxygen for fish
in cool water.
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b. pressure (If pressure is increased, more
solute will stay in solution) Ex. Sodas lose
their bubbles when the can is opened.
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(No Transcript)
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b. pressure (If pressure is increased, more
solute will stay in solution) Ex. Sodas lose
their bubbles when the can is opened. c.
nature of the solvent and solute (Organic
solvents dissolve organic solutes. Inorganic
solvents dissolve inorganic solutes. Water is
an exception.
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Obj 11 A saturated solution at a given
temperature will NOT dissolve any more solute.
A saturated solution has the MAXIMUM amount of
solute dissolved for that temperature.
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Obj 11 If more solute can still be
dissolved, it is called an unsaturated solution.

Since some solute has settled, is this
unsaturated or saturated?
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Obj 11 A supersaturated solution contains MORE
solute than a saturated one has at that
temperature. (MORE than normal)
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Obj 12 Solubility curve - a graph showing how
much solute is dissolved in a solvent over a
range of temperatures.
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Obj 12 The solubility curves (lines) shown on
the graph represent saturated solutions.
HINT SAT on the line
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Obj 12 Any amounts of solute dissolved that
are UNDER the normal amounts shown on the
solubility curves would make unsaturated
solutions
HINT UNder the line.
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Obj 12 Any amounts of solute dissolved that
are ABOVE the normal amounts shown on the
solubility curves would make supersaturated
solutions
HINT SUPER means EXTRA higher.
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Obj 13 The physical methods of separating
mixtures are a. Evaporation is removing water
from a solution or removing the liquid portion
from a mixture without adding heat.
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Obj 13 The physical methods of separating
mixtures are a. Evaporation is removing water
from a solution or removing the liquid portion
from a mixture without adding heat. b.
Distillation is the separation of two liquids
because of a difference in boiling points.
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Distillation- separating 2 liquids because of
differences in boiling points
Cooling water in
Part of the chemical boils, turns to steam
Condenser cools the vapor into liquid
Pure distilled chemical is left
Cooling water out
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Obj 13 The physical methods of separating
mixtures are b. Distillation is the
separation of two liquids because of a difference
in boiling points. c. Filtration - the
removal of insoluble solids from a liquid
mixture. Filtrate - the liquid portion
of the filtered mixture which passes
through the filter. Ex. Coffee that
you drink is a filtrate since it went
through a filter.
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c. Filtration - the removal of insoluble solids
from a liquid mixture. Ex. Gold nuggets
Filtrate - the liquid portion of the filtered
mixture which passes through the filter.
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To make a supersaturated solution, extra solute
is dissolved by warming the solution a bit more.
Then, the solution is cooled gently, and the
extra solute stays dissolved.
When a seed crystal is added, the extra solute
can no longer stay dissolved and it
recrystallizes.
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Obj 14 Adding solute particles a. raises
the boiling point of a solution. Ex.
Boiling sugar water is hotter than
plain boiling water. Water with
antifreeze does not turn to gas as
easily as water without antifreeze.

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Obj 14 The addition of solute particles a.
raises the boiling point of a solution. b.
lowers the freezing point of a solution. Ex.
Plain water is frozen at 0oC while water
with antifreeze does not turn into solid until
-10oC.EX. Frozen iceburgs (salty ocean water)
are COLDER than normal ice cubes More solute is
dissolved!
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Obj 15 Comparing solutions, colloids and
suspensions
Description
Solutions
Colloids
Suspensions
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Description Settles upon standing?
Solutions NO
Colloids NO
Suspensions YES
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Is orange juice a solution?
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Obj 15
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If the contents of this beaker was poured into a
filter, would all the materials go through the
filter? Are the contents an example of a
solution?
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Obj 15
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What is the size of the particles in the bottom
of this beaker?
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Obj 15
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Which one scatters light? Which one is a solution?
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Obj 15
Colloids YES Maybe
Suspensions YES NO
Description Scatters Light Homogeneous?
Solutions NO YES
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Obj 15
Colloids Maybe Maybe
Suspensions NO YES
Description Homogeneous? Heterogeneous?
Solutions YES NO
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muddy water
Spiced cider
Oil water
broth
fog
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Obj 15 What are the EXAMPLES of colloids and
suspensions, solutions ?
Colloids maybe maybe smoke
Suspensions NO YES orange juice
Description Homogeneous? Heterogeneous? Examples

Solutions YES NO iced tea