As you come in, The Materials: –Paper and pencil –Pick up calendar, assessment plan, and...
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As you come in, • The Materials: – Paper and pencil – Pick up calendar, assessment plan, and practice packet • The Plan: – Self-Assessment: Cumulative Quiz 7 – Visual/Auditory Activity: Solubility notes, including polarity, solubility rules, exceptions to rules, and solubility graphs – Collaborative Partners: Interpreting Graphics WS – Solubility Graphs – Individual Practice : Complete Interpreting Graphics WS – Practice Packet: “Reading Solubility Graphs” and “Worksheet: Solubility Graphs” • The Assessment: – Solubility Graph Quiz- Wednesday – Concentration Quiz - Friday Musical Theme: Motown Monday
As you come in, The Materials: –Paper and pencil –Pick up calendar, assessment plan, and practice packet The Plan: –Self-Assessment: Cumulative Quiz 7
As you come in, The Materials: Paper and pencil Pick up
calendar, assessment plan, and practice packet The Plan:
Self-Assessment: Cumulative Quiz 7 Visual/Auditory Activity:
Solubility notes, including polarity, solubility rules, exceptions
to rules, and solubility graphs Collaborative Partners:
Interpreting Graphics WS Solubility Graphs Individual Practice:
Complete Interpreting Graphics WS Practice Packet: Reading
Solubility Graphs and Worksheet: Solubility Graphs The Assessment:
Solubility Graph Quiz- Wednesday Concentration Quiz - Friday
Musical Theme: Motown Monday
Slide 3
Georgia Performance Standard SC7: Students will characterize
the properties that describe solutions and the nature of acids and
bases.
Slide 4
The Water Molecule Triatomic Covalent Polar bonds & polar
overall Bent at 105 angle
Slide 5
Intermolecular Forces Polar molecules are attracted to one
another by dipole forces Water is attracted to other water
molecules by a special dipole force, a hydrogen bond
Slide 6
Water Solutions Chemically pure water never exists in nature
because water dissolves so many substances. textbook Universal
solvent Aqueous solutions
Slide 7
Water Solutions Ionic compounds most readily dissolve in water
due to extreme polarity Polar covalent compounds also dissolve in
water Nonpolar compounds dont
Slide 8
Solvation of Ionic Compounds
Slide 9
A Few Exceptions... Remember the solubility rules... In some
ionic compounds, the ions are so attracted to each other that they
wont break apart and dissolve. These are INSOLUBLE ionic
compounds.
Slide 10
Solvation of Covalent Compounds Covalent compounds do NOT break
apart in water when dissolving. Solvation of covalent compounds
means that each solute molecule is surrounded by water
molecules.
Slide 11
Conductors In general, aqueous solutions of ionic compounds are
electrolytes. Generally, aqueous solutions of covalent compounds
are nonelectrolytes.
Slide 12
As you come in, The Materials: Paper, calculator, practice
packet and pencil The Plan: Opening Activity: Go over Unit 8 Test
Self-Assessment: Review Solubility Graph, Answer questions in
packet and on Interpreting Graphics WS Visual/Auditory Activity:
Concentrations notes, including molarity and molality Individual
Practice: Molarity & Molality Practice 15-2 Practice Problems
WS 1-5, 7, 9, 13, 17 The Assessment: Solubility Graph Quiz-
Wednesday Concentration Quiz - Friday Musical Theme: 2-Step
Tuesday
Slide 13
Solution Vocabulary Solute: Dissolves in the solvent Soluble:
Able to be dissolved in the solvent (applicable to any states of
matter) Insoluble: Unable to be dissolved in the solvent
(applicable to any states of matter) Miscible: Able to be dissolved
in the solvent (applicable to liquid/liquid solutions) Immiscible:
Unable to be dissolved in the solvent (applicable to liquid/liquid
solutions)
Slide 14
Solubility Vocab Unsaturated: less than maximum amount of
solute is dissolved in the solvent Saturated: maximum amount of
solute is dissolved in the solvent Supersaturated: special
conditions have been created to dissolve more than maximum amount
of solute in the solvent
Slide 15
Determines IF Solute Will Dissolve... The nature of the solvent
and solute governs whether a solute will solvate in a particular
solvent. Specifically, the nature of the intramolecular bond. Polar
molecules will solvate with polar molecules. Nonpolar molecules
will solvate with nonpolar molecules. BUT, polar and nonpolar will
not form solutions together.
Slide 16
Determines Speed of Dissolving 1.Agitation: Create more
collisions mechanically 2.Temperature: More kinetic energy creates
more collisions 3.Surface Area: Dissolving process is a surface
phenomenon, the more surface of the solute that is exposed the
faster the solvation BRING SOLUTE IN CONTACT WITH SOLVENT
Slide 17
Determines How Much Will Dissolve 1.Temperature: solubility of
solid solute increases as the temp. increases; solubility of
gaseous solute decreases as temp increases ex. Hot water bubbles,
thermal pollution 2. Pressure: solubility of gaseous solute
increases as the pressure increases -Henrys Law ex. Soft drinks
SOLUBILITY: HOW MUCH WILL DISSOLVE
Slide 18
Temperature & Solubility Higher the temperature, the more
solid will dissolve in a liquid Higher the temperature, the less
gas will dissolve in a liquid
Slide 19
Henrys Law: Pressure & Solubility At a given temperature,
the solubility of a gas is proportional to the pressure of the gas
above the liquid. Page 506 The higher the pressure, the more carbon
dioxide will dissolve in the syrup giving a less flat taste.
Slide 20
Solubility Graph
Slide 21
Concentration of Solutions The concentration of a solution is a
measure of how much solute is dissolved in a specific amount of
solvent or solution. Molarity: most common units of solution
concentration; # of moles solute dissolved in one liter of the
solution
Slide 22
Molarity: moles of solute liter of solution If given grams,
remember to change it to moles.
Slide 23
Example 15.3 (page 531) Calculate the molarity of a solution
prepared by dissolving 11.5 g of solid NaOH in enough water to make
1.50L of solution. Example 15.4 (page 532) Calculate the molarity
of a solution prepared by dissolving 1.56 g of gaseous HCl into
enough water to make 26.8 mL of solution.
Slide 24
molality: moles of solute kg of solvent If given grams,
remember to change it to moles. The most common concentration term
in chemistry is Molarity (M), but chemists also report
concentration in molality (m) sometimes.
Slide 25
The front of the last page in the calculations packet refers to
Molality. Complete 1 (a), 2 (a), 3 (b), and 4 (b). NOTE: Questions
3 and 4 will require you to manipulate the equation. Question 4
might even require that you change the units of your answer at the
end of the calculation.
Slide 26
As you come in, The Materials: Paper, calculator, practice
packet and pencil Get a remote control The Plan: Opening Activity:
Go over Solubility Graphs Assessment: Solubility Graph Quiz
Kinesthetic Activity: Preparing a Solution Lab Individual Practice:
Molarity & Molality Practice 15-2 Practice Problems WS 6, 8,
10-12, 14-16 The Assessment: Concentration (Molarity &
Molality) Quiz Friday (25pts) Musical Theme: Relaxing
Wednesday
Slide 27
Preparing a Solution in the Lab Youve learned about
concentration (Molarity and molality). Therefore, you should be
able to create your own solutions for use in the lab from now on.
Example: 0.5 M HCl reacts with Mg(s) If I gave you HCl powder, what
would you do to make the solution? Watch these kids, and assess
your plan. Watch these kids Choose a lab group and station. Draw an
assignment from the cup, and make the solution. Write your steps
(including materials) as you go. ALSO: Solve 15-2 Practice Problems
WS 6, 8, 10-12, 14-16.
Slide 28
As you come in, The Materials: Paper, calculator, practice
packet and pencil The Plan: Opening Activity: Molarity/molality
Practice Visual/Auditory Activity: Dilutions and Stoichiometry
Individual Practice: Solutions Stoichiometry in practice packet The
Assessment: Concentration (Molarity & Molality) Quiz Friday
(25pts) Musical Theme: Disney Day
Slide 29
Diluting Solutions If you already have a solution molarity, but
you want a different molarity: Example: Your lab asks you to use
250 mL of 0.25M HCl, but you only find a jug of 6M HCl in the
stockroom. USE THIS EQUATION: M 1 V 1 = M 2 V 2
Slide 30
Example 15.8 (page 539) What volume of 16 M sulfuric acid must
be used to prepare 1.5 L of a 0.10 M H 2 SO 4 solution? *Be sure to
solve the Dilution Worksheet in your practice packet!
Slide 31
Using Molarity as a Conversion Factor You have learned to
calculate molarity using the equation: Molarity = moles of solute /
liter of solution Did you realize that the calculation is simply a
ratio of solute to solution? Ratios (ie mole ratios, energy to mole
ratios) can be used as conversion factors in stoichiometry.
THEREFORE, molarity can be written into our dimensional analysis
charts to solve stoichiometry problems.
Slide 32
Solutions Stoichiometry What volume of 1.5 M HCl is needed to
react with 21.5 grams of NaOH? What is the molarity of a solution
of H2S if 48.5mL are required to titrate 35.6mL of 0.35M Fe(OH)3
solution? A white precipitate forms when 200 mL of 0.200M K3PO4
solution is mixed with 300 mL of 0.250 M CaCl2 solution. What mass
of precipitate will form? BE SURE TO SOLVE THE PRACTICE PROBLEMS IN
YOUR PACKET!
Slide 33
Diluting A Solution Lab Purpose: See group assignment
Materials: What else would you need? Safety: What should you think
about? Procedure: Part One: Making the solution from scratch. Part
Two: Dilution. Write it out step by step! Results &
Conclusions: How do you need to revise your procedure? MUST HAVE
NOTEBOOK APPROVED BEFORE MOVING TO STATION
Slide 34
As you come in, The Materials: Remote control, paper, pencil,
calculator, practice packet The Plan: Opening Activity:
Concentration Quiz Self-Assessment Activity: Go over Stoichiometry
Exit Question Visual/Auditory Activity: Colligative Properties
notes Individual Practice: Solving 15-4 colligative properties
calculations in packet The Assessment: Colligative Properties Quiz
(15 pts) - Tuesday Musical Theme: Greatest Hits Friday
Slide 35
Physical properties of solution are different from the physical
properties of the solvent. Some properties are different simply
because there are foreign particles (solute) in the solvent.
Colligative properties of solutions depend only on the number of
solute particles.
Slide 36
Number of Particles of Solute Think back to what youve learned
about ionic and covalent compounds dissolving in water. Ionic
compounds DISSOCIATE as they dissolve. Covalent compounds do NOT
dissociate as they dissolve. Apply this idea. How many solute
particles will 1 piece of NaCl add to a solvent? Answer: 2 (Na+ and
Cl-)
Slide 37
Applying the Concept Further How many solute particles will 1
piece of magnesium phosphate add to a solvent? Mg 3 (PO 4 ) 2
breaks into 3 Mg 2+ ions and 2 PO 4 3- ions. Answer: 5 solute
particles How many solute particles will 1 piece of sugar add to a
solvent? Sugar is covalent. Answer: 1 solute particle Finally,
which of the two above will affect a colligative property the
most?
Slide 38
Boiling point is changed when solute is added to the solvent.
Boiling point elevates when a solute is added to a solvent. The
solution requires more energy to reach boiling. Example: Salt water
will not boil at 100C. It will boil at a HIGHER temp.
Slide 39
As you come in, The Materials: Paper and pencil The Plan:
Visual/Auditory Activity: Review colligative properties
Collaborative Partners: Colligative properties practice The
Assessment: Colligative Properties Quiz: Tuesday Cumulative Quiz:
Thursday Unit Test: Friday Musical Theme: Motown Monday
Slide 40
Calculating the NEW Boiling Pt. T b = K b m i T b = change in
boiling pt. K b = boiling point constant for the solvent (will be
given) m = molality i = number of ions present in the solute (USE
ONLY WITH IONIC SOLUTES!)
Slide 41
Example of Boiling Pt. Calculation What is the boiling point
when 15.0g NaCl is dissolved into 200 mL of water? (K b of water is
0.52 C/m) T b = K b m i You are solving for T b, and you have the K
b to use. m =Youll need to calculate the molality from the info in
the question. (change 15.0 g of NaCl to moles and 200 mL to kg and
plug in) i = Finally, is the solute ionic? YESNaCl is ionic and
will give TWO ions when dissolved.
Slide 42
CHALLENGING: How many grams of NaCl would need to be added to
the water to change the boiling temperature of 200 mL to 110C? K b
of water = 0.52C/m 10C = m(0.52)(2) m = 9.62 9.62m = mole/0.2kg
mole = 1.92 mole NaCl 112.2 grams NaCl
Slide 43
Freezing point is changed when solute is added to the solvent.
Freezing point depresses when a solute is added to a solvent. The
solution requires a lower temp to reach freezing. Example: Salt
water will not freeze at 0C. It will freeze at a LOWER temp.
Slide 44
Calculating a NEW Freezing Pt. T f = K f m i T f = change in
freezing pt. K f = freezing point constant for the solvent (will be
given) m = molality i = number of ions present in solute (USE ONLY
WITH IONIC SOLUTES)
Slide 45
Example of Freezing Pt. Calculation What is the freezing point
when 15.0g NaCl is dissolved into 200 mL of water? (K f of water is
1.86 C/m) T f = K f m i You are solving for T f, and you have the K
f to use. m =Youll need to calculate the molality from the info in
the question. (change 15.0 g of NaCl to moles and 200 mL to kg and
plug in) i = Finally, is the solute ionic? YESNaCl is ionic and
will give TWO ions when dissolved.
Slide 46
CHALLENGING: How many grams of NaCl would need to be added to
the water to change the freezing temperature of 200 mL to -8C? K f
of water = 1.86C/m 8C = m(1.86C/m)(2) molality = 2.15 2.15 =
mole/0.2kg mole = 0.43 mole NaCl 25.14 grams NaCl
Slide 47
Practice Practice Practice! The 15-4 Practice Problems in your
practice packet are boiling point/freezing point calculations. The
key is posted at the front of the classroom. Colligative Properties
Quiz - Tuesday PLEASE SOLVE MANY OF THESE PROBLEMS! Youll see
several on Fridays test.
Slide 48
As you come in, The Materials: Paper, pencil, calculator,
practice packet The Plan: Opening Activity: We Solute YouWe Solute
You Collaborative Practice: Solving Colligative properties problems
in packet Pre-Lab Activity: Prepare for Ice Cream Lab The
Assessment: Colligative Properties Quiz (15 pts) - Tuesday Musical
Theme: Motown Monday
Slide 49
About.comChemistry Ice has to absorb energy in order to melt,
changing the phase of water from a solid to a liquid. When you use
ice to cool the ingredients for ice cream, the energy is absorbed
from the ingredients and from the outside environment (like your
hands, if you are holding the baggie of ice!). When you add salt to
the ice, it lowers the freezing point of the ice, so even more
energy has to be absorbed from the environment in order for the ice
to melt. This makes the ice colder than it was before, which is how
your ice cream freezes. Ideally, you would make your ice cream
using 'ice cream salt', which is just salt sold as large crystals
instead of the small crystals you see in table salt. The larger
crystals take more time to dissolve in the water around the ice,
which allows for even cooling of the ice cream.