Chapter 7: Solutions
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I can distinguish between homogeneous and heterogeneous mixtures
I can compare the properties of colloids and solutions
I can give examples of solutions that are liquids or gases
I can relate the ability of a solvent to dissolve a solute
I can describe ways to increase the rate at which a solute dissolves in a solvent
I can describe dilute, concentrated, saturated, unsaturated, and supersaturated
solutions
Solutions
A solution is a homogeneous mixture composed of only
one phase.
• They can be solid, liquid or gaseous.
Important Vocabulary this Chapter
Homogeneous Mixture – a mixture that is the same
throughout
• It is all the same color, with no pieces or parts that look
different
Solution – A homogeneous mixture of two or more
substances that’s are spread throughout
Solute – Helps make a solution, this is what dissolves
(usually solid) in the solution
Solvent – Helps make a solution, this is what makes the
solute dissolve (usually liquid) in the solution
Parts of a Solution
(two parts = solvent & solute)
Solvent: a substance that
dissolves a solute in a
solution
Water is called the universal
solvent because it dissolves
more substances than any
other solvent
Example: Water
Solute: The substance that
is dissolved
The “thing” disappearing
Example: Sugar
There are 3 Types of Solutions
Saturated (contains all the solute
it can hold at a given
temperature)
Unsaturated (can still dissolve
more solute)
Supersaturated (contains more
solute than it would normally at a
given temperature)
Special Names for Everything!
 There are also different names for the different types of
homogenous mixtures.
 Solution is the general term used to describe homogenous
mixtures with small particles.
 Colloids – are solutions with bigger particles.
• Colloids are usually foggy or milky when you look at them.
• In fact, milk is an colloid and fog is a colloid!
What Changes the Speed of Solubility?
Concentration
• The solute and solvent interact with each other until the concentration
of the two substances is equal throughout the system.
Temperature
• In general more solute dissolves in a solute
with higher temperatures
• Have more kinetic energy to overcome the attractive forces between
bonds
Stirring
• Stirring will increase the rate of dissolving
 Particle Size
• Larger particles take longer to dissolve
Pressure
• More pressure causes solutes to dissolve faster
Are Solutions Always Liquids?
No!
• Solutions can also be gases dissolved in liquids,
such as carbonated water or pop!
How Can You Separate a Solution?
If you wanted to separate a solution, how could
you do it?
• Add Heat
 Remove the solute by adding heat
 This evaporates the solvent, leaving the solute
• Distilling
 Only the solvent remains, separating out the solute
• Filtering
 If the solution is supersaturated, you can remove the
remaining solid by using filter paper to catch the solid while
the liquid falls through
Can You Dissolve More Solute in Warm or Cool
Water?
• The cold water can’t dissolve as much as the hot water
• When the solution can no longer dissolve the solute it becomes a
'saturated solution', this means that the solute starts forming on
the bottom of the container
• The reason the hot water dissolves more is because it has faster
moving molecules which are spread further apart than the
molecules in the cold water. With bigger gaps between the
molecules in the hot water, more solute molecules can fit in
between.