lecture free teaching: properties of solutions
DESCRIPTION
Lecture Free Teaching: Properties of Solutions. 2010 KSTA Conference Lisa Devillez Marshall County High School. Lecture Free Teaching (LFT). Note-making as “homework” / Vodcasting foundational lectures improves textbook reading skills classroom discussion focused on student questions - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Lecture Free Teaching: Properties of Solutions](https://reader035.vdocument.in/reader035/viewer/2022062720/568134a8550346895d9bb433/html5/thumbnails/1.jpg)
Lecture Free Teaching: Properties of Solutions
2010 KSTA ConferenceLisa DevillezMarshall County High School
![Page 2: Lecture Free Teaching: Properties of Solutions](https://reader035.vdocument.in/reader035/viewer/2022062720/568134a8550346895d9bb433/html5/thumbnails/2.jpg)
Lecture Free Teaching (LFT)
• Note-making as “homework” / Vodcasting foundational lectures
– improves textbook reading skills– classroom discussion focused on
student questions– more class time for labs– more time for "advanced" problems
• Active Learning!
![Page 3: Lecture Free Teaching: Properties of Solutions](https://reader035.vdocument.in/reader035/viewer/2022062720/568134a8550346895d9bb433/html5/thumbnails/3.jpg)
Lecture Free Teaching (LFT)
• Clear and concise objectives– Notes– Homework– Tests
• Mastery learning & standards-based grading are complementary LFT
![Page 4: Lecture Free Teaching: Properties of Solutions](https://reader035.vdocument.in/reader035/viewer/2022062720/568134a8550346895d9bb433/html5/thumbnails/4.jpg)
Lecture Free Teaching (LFT)
• Class time– Opportunity for student feedback– Collection of active learning activities– Limit “lectures” (ie., passive instruction)
in both frequency and time
![Page 5: Lecture Free Teaching: Properties of Solutions](https://reader035.vdocument.in/reader035/viewer/2022062720/568134a8550346895d9bb433/html5/thumbnails/5.jpg)
Solutions
• The perfect “unit” for LFT and developing lab skills
• Narrowed scope of objectives based on difficulties of former students
• Selected / modified labs to address all of the objectives
![Page 6: Lecture Free Teaching: Properties of Solutions](https://reader035.vdocument.in/reader035/viewer/2022062720/568134a8550346895d9bb433/html5/thumbnails/6.jpg)
Objectives
• 5.1 Define units of concentration, mass percent, ppm, mole fraction, molarity, and molality, and be able to calculate each from appropriate data.
• 5.2 Be able to convert a concentration from one unit to the other.
• 5.3 Be able to calculate solution concentration for single and serial dilutions.
• 5.4 Describe the effect of solute (or solvent) concentration on boiling point and freezing point. Be able to calculate any of these effects from concentration data for nonelectrolyte solutes.
![Page 7: Lecture Free Teaching: Properties of Solutions](https://reader035.vdocument.in/reader035/viewer/2022062720/568134a8550346895d9bb433/html5/thumbnails/7.jpg)
The Labs: General Format
• Prepare a solution of the assigned concentration.• Measure property for 5 standard solutions (teacher-
prepared) and student solution.• Graph property vs. concentration for the standards• Use equation for trend line and measurement for
student solution to verify its concentration
![Page 8: Lecture Free Teaching: Properties of Solutions](https://reader035.vdocument.in/reader035/viewer/2022062720/568134a8550346895d9bb433/html5/thumbnails/8.jpg)
The Labs: Documentation
• Data Tables• Standards graphs
– Trend line– Correlation value (R2)
• Calculations– Verification of student solution concentration– % error
![Page 9: Lecture Free Teaching: Properties of Solutions](https://reader035.vdocument.in/reader035/viewer/2022062720/568134a8550346895d9bb433/html5/thumbnails/9.jpg)
Glucose Standards
Grams in 500ml H2O
Density(18.3ᵒC)
%w/w Molality(mol/kg)
Molarity(mol/L)
26.3 1.015 5 0.292 0.282
55.56 1.040 10 0.617 0.641
125 1.075 20 1.39 1.492
214.29 1.110 30 2.38 2.640
333.33 1.155 40 3.70 4.126
![Page 10: Lecture Free Teaching: Properties of Solutions](https://reader035.vdocument.in/reader035/viewer/2022062720/568134a8550346895d9bb433/html5/thumbnails/10.jpg)
Glucose Standards
Grams in 500ml H2O
ppm
0.15 300
0.25 500
0.35 700
0.45 900
0.55 1100
![Page 11: Lecture Free Teaching: Properties of Solutions](https://reader035.vdocument.in/reader035/viewer/2022062720/568134a8550346895d9bb433/html5/thumbnails/11.jpg)
Hydrometry : Specific gravity
![Page 12: Lecture Free Teaching: Properties of Solutions](https://reader035.vdocument.in/reader035/viewer/2022062720/568134a8550346895d9bb433/html5/thumbnails/12.jpg)
Refractometry: Snell’s Law
“The determination of the concentrations of sugar solutions by Laser Refractometry” Hughes & JelksJCE November 1988
![Page 13: Lecture Free Teaching: Properties of Solutions](https://reader035.vdocument.in/reader035/viewer/2022062720/568134a8550346895d9bb433/html5/thumbnails/13.jpg)
Refractometry: Snell’s Law
![Page 14: Lecture Free Teaching: Properties of Solutions](https://reader035.vdocument.in/reader035/viewer/2022062720/568134a8550346895d9bb433/html5/thumbnails/14.jpg)
Colligative Properties: Freezing point
• Assigned 2.0M 100mL• Standards in molalities
![Page 15: Lecture Free Teaching: Properties of Solutions](https://reader035.vdocument.in/reader035/viewer/2022062720/568134a8550346895d9bb433/html5/thumbnails/15.jpg)
Spectroscopy: Beer’s Law
• 5mL glucose solution & 5mL Benedict’s• Spec 20; 730nm; distilled water blank
![Page 16: Lecture Free Teaching: Properties of Solutions](https://reader035.vdocument.in/reader035/viewer/2022062720/568134a8550346895d9bb433/html5/thumbnails/16.jpg)
Calibration Curves
0 5 10 15 20 25 30 35 40 450
0.25
0.5
0.75
1
1.25
1.5
1.75
2
2.25
2.5
2.75
3
3.25
3.5
3.75
4
4.25
4.5
4.75
f(x) = 0.109268292682927 x − 0.0146341463414634R² = 0.996178166909874
Refractometry
w/w %
Disp
lacm
ent
![Page 17: Lecture Free Teaching: Properties of Solutions](https://reader035.vdocument.in/reader035/viewer/2022062720/568134a8550346895d9bb433/html5/thumbnails/17.jpg)
Calibration Curves
0 0.25 0.5 0.75 1 1.25 1.5 1.75 2 2.25 2.5 2.750.95
0.975
1
1.025
1.05
1.075
1.1
1.125
1.15
1.175
f(x) = 0.0536440111648864 x + 1.00584436219856R² = 0.966101076963197
Hydrometry
Molarity
Spec
. Gra
vity