JULIE A. WASYLNKA

Concept Presentation:Solutions and Solubility

Chemistry 11U

Outline of Presentation

Background Information on solutions and solubilityCurriculum placementOverall and specific expectationsLesson sequence/teaching strategies (A&E embedded)Common misconceptions STSEReferences

Background Information

Big Ideas from the CurriculumProperties of solutions can be described qualitatively

and quantitatively, and can be predicted.Living things depend for their survival on the unique

physical and chemical properties of water.People have a responsibility to protect the integrity of

Earth’s water resources

Background Information

Why study solutions?The majority of chemical processes are reactions that

occur in solution.

Important industrial processes often utilize solution chemistry.

"Life" is the sum of a series of complex processes occurring in solution.

Air, tap water, beverages, and household cleaners are common examples of solutions (Lagowski, 2004).

Curriculum placement

Previously learned concepts essential for success:Intermolecular forcesBonding/lewis structuresAtomic radius/ionic radiusStoichiometry

Matter and Bonding

Chemical reactions Stoichiometry Solution

sGases

September June

Curriculum expectations

Overall

Specific expectations

Lesson 1

Lesson 2, 4

Lesson 3

Lesson 5 ,6

Lesson Sequence

1) Unique properties of water and case study

2) Introduction to solutions

3) Factors affecting solubility and rates of dissolving

4) Factors affecting solubility part II

5) The solubility rules

6) Mystery compounds mini-lab

Lesson 1: Case studyThe use of bottled water and its impact on the environment

Demos on the properties of waterShow video clipPut students in teacher-chosen groups

Distributes case study Briefly discusses what students will be doing

MI: Interpersonal, Logical

A for L: Class discussion and observation

Class management of the case study

Step Task Time (min)1 Read Part I of the case. 52 Discuss Sally’s mother’s dilemma, using it as a

tool to direct class discussion to the background information in Part II

10-15

3 Read Part II of the case. 54 Groups discuss the questions at the end of

Part II—have them prepare answers to turn in.15-20

5 Class discussion—emphasize the interrelatedness of the issues.

20

Lesson 2: Introduction to Solutions

Introductory powerpoint slides Review of terminology (solution, soluble, etc.) Types of solutions (solid – liquid, liquid-liquid etc.)

- Video Clip: http://www.mhhe.com/physsci/chemistry/essentialchemistry/flash/molvie1.swf

Mini-labs

MI: Visual, Tactile, Auditory, Interpersonal

A for L: Exit pass

Lesson 3: Factors affecting Solubility and Rates of dissolving Factors affecting solubility of compounds

(temperature, pressure and nature of solute/solvent) Review intermolecular forces and introduce ion-

dipoles Rates of dissolving (agitation, particle size,

temperature) Polarity and solubility mini-lab

MI: Tactile, Logical, Interpersonal, Visual, Kinesthetic

A for L: Class observation/ discussion

Lesson 4: Factors affecting Solubility II: Polar and non-polar solvents mini-lab

Substance Water soluble (S, SS, NS)

Oil soluble(S, SS, NS)

ureaiodineAmmonia (dilute)naphthalenecopper(II) sulfatesodium chloride   ethanolA as L: Peer assessment

Lesson 5: The Solubility Rules, Part I

Discussion on atomic size and charge of ions (socratic)

How to use solubility tablesMini-Lab on known precipitation reactions

MI: Interpersonal, Visual, Tactile, Logical

A for L: Exit pass

Lesson 6: The Solubility Rules, Part II

Teacher Review solubility rules (veritech) Mini-lab with unknown compounds (A of L: structured/guided

inquiry)

DI Preconstructed data table or ask them to construct their own

data tables Hints with the analysis Greater number of unknowns (challenge)

Lab Safety

Wear goggles when performing labs/mini-labs.Dispose of hazardous chemicals in the appropriate

chemical waste containers

Misconceptions with this topic: #1

Difficulties determining whether a solvent/solute is polar or non-polar

StrategiesReview concepts of intermolecular forcesHave students draw out lewis structures

of the solvents

D.I. Students can build the models

Misconception # 2

True or false: Increasing the temperature of a solution increases the solubility of solid and gases solutes.

False:• The solubility of gaseous solutions

decreases with increasing temperature.

Suggested Teaching Strategies• Demo with carbonated beverages

Solubility tables are difficult to read

SuggestionsStudents create their own tablesPneumonic?

“CHOPS NAAA.” Solubility is explained from simple physical

principles Coulomb’s Law Atomic radii

Misconception #3

Dualistic treatment of solubility - Substances are only classified as soluble

or insoluble, with no mention of the range of solubility values

SuggestionsMore solubility data is included early in

the discussion

Misconception #4

STSE

Water purification/Waste water treatment

IV solutions

Air quality

Reactions of the human body occur in solution

Metal alloys: brass, bronze, steel

Acknowledgements

LakshmiJanineMartyAll my colleagues

References

Blake, B. 2003. J. Chem. Ed. Solubility Rules: Three Suggestions for Improved Understanding

May, Lindsay Jessica Kotke, and Charles R. Bomar, But It’s Just a Bottle of Water... University of Wisconsin–Stout , 2006. National center for case study teachng in Science. http://www.sciencecases.org/bottled_water/bottled_water.asp

“ Chemistry. Foundations and Applications.” Lagowski, J. J. 2004. http://findarticles.com/p/articles/mi_gx5216/is_2004/ai_n19132971/?tag=content;col1. Retrived July 16, 2010.

McGraw Hill Higher Education (Solvation Animation) http://catalogs.mhhe.com/mhhe/home.do

References

Solubility Rules and the Mystery Solutions. Ohio Department of Education. http://ims.ode.state.oh.us/ODE/IMS/Lessons/Content/CSC_LP_S06_BA_L11_I01_01.pdf

http://www.nclark.net/molecular_polarity_and_solubility_lab/doc

http://dwb.unl.edu/Chemistry/MicroScale/MScale26.html#TG%20Description

The Water bottle problem: http://www.youtube.com/watch?v=flTbLnn5w_0

http://www.northland.cc.mn.us/biology/Biology1111/animations/dissolve.html