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ANSWERS Unit 9 Study Guide (1)

Unit 9 Study Guide-Solutions
Summarize solubility:
The ability of something to dissolve into a liquid. OR the extent to which a solute dissolves in
a solvent.
Explain the difference between a solute, solvent, and an aqueous solution:
A solUte is the substance being dissolved (“U get in there and dissolve…”)
The solvent is the liquid the solUte is being dissolved in and an aqueous solution is the liquid
solvent that has a solute dissolved in it.
List factors that influence solubilities and rates of dissolution:
Temperature, pressure, stirring, surface area (think about the time you crushed an alka seltzer
tablet vs. when it was dissolved whole or a sugar cube verses grained sugar…)
Describe the chemical and physical properties of water:
Physical: solid, liquid, gas,boiling-freezing point, surface tension.
Chemical: polarity, universal solvent, vital to life, etc
What is the shape of a water molecule?
Why is water considered the universal solvent?
Water is called the 'universal solvent' because it dissolves
more substances than any other liquid. This means that
wherever water goes, either through the ground or through
our bodies, it takes along valuable chemicals, minerals, and
Need to understand “like attracts like” (polar substances
able to dissolve, non-polar=not)
Polarity (need to understand electrical charges and “like attracts like”)
Universal solvent because it can dissolve more substances than any other liquid.
What makes water polar?
Water is polar because of its shape- one side is positively charged (H) and one side that is
negatively charged (O). The molecule is made up of two hydrogen atoms and one oxygen
atom. The bonds between the atoms are called covalent bonds, because the atoms share
Types of Solutions – describe each type of solution in the space below:
Electrolyte​ - ​ a chemical compound that conducts electricity by changing into
ions when melted or dissolved into a solution​.
Nonelectrolyte​ - ​opposite of above...
Unsaturated​ - ​ the solute concentration is lower.... A saturated solution contains
more solute per volume of solution... (everything is dissolved and there’s room
for more…)
Saturated​ -​ If no additional solute can dissolve in a solution, that solution is said
to be saturated.
Supersaturated​ -​ contains more dissolved material than could be dissolved.
What are some factors that could affect solubility:
Solubility depends on temperature. Raising the temperature of a solution may
even turn a saturated solution into an unsaturated on. Or, lowering the
temperature of a solution may change it from unsaturated to saturated.
Increased temperature causes an increase in kinetic energy. The higher kinetic
energy causes more motion in the gas molecules which break bonds and escape
from solution.
(LOOK AT YOUR SOLUBILITY GRAPH) ​As the temperature increases, the
solubility of a gas decreases as shown by the downward trend in the graph
What would cause a precipitate to form from a mixture of compounds?
Compounds or elements that are insoluble, since they won’t dissolve, they form
a solid and settle out ...
What is molarity?
Moles of solute per liter of solution
What is the formula used to calculate molarity? ​1000mL=1L
M​=​ ​Moles of solute
​liter of solution
Units: mol/L or M