LESSON PLAN
Name: Maryann Sorey
Title of lesson: Making Dilutions
Date of lesson: N/A
Length of lesson: (2) 50-minute class periods
Description of the class:
Name of course: AP Chemistry
Grade level: 12th
Honors or regular: AP
Source of the lesson :
Fundamental technique in chemistry, no specific source. Engagement activity is from Is Dilution the Solution to Pollution? From Laying the Foundation in Middle Grades Life and Earth Science, Advanced Placement Strategies, Inc.
TEKS addressed:
Give identification number and letter and write out the TEKS.
(1) Scientific processes. The student, for at least 40% of instructional time, conducts field and laboratory investigations using safe, environmentally appropriate, and ethical practices. The student is expected to:
(A) demonstrate safe practices during field and laboratory investigations; and
(B) make wise choices in the use and conservation of resources and the disposal or recycling of materials.
(2) Scientific processes. The student uses scientific methods during field and laboratory investigations. The student is expected to:
(A) plan and implement investigative procedures including asking questions, formulating testable hypotheses, and selecting equipment and technology;
(B) collect data and make measurements with precision;
(C) express and manipulate chemical quantities using scientific conventions and mathematical procedures such as dimensional analysis, scientific notation, and significant figures;
(D) organize, analyze, evaluate, make inferences, and predict trends from data; and
(E) communicate valid conclusions.
(3) Scientific processes. The student uses critical thinking and scientific problem solving to make informed decisions. The student is expected to:
(D) describe the connection between chemistry and future careers
Additionally, this project fits within the scope of “Guide for the Recommended Laboratory Program” published by the College Board for AP classes. Please see
http://www.collegeboard.com/prod_downloads/ap/students/chemistry/ap03_chemistry.pdf
I. Overview
Students will analyze solution using colorimetric analysis .The skills developed in this lab are recommended by “Guide for the Recommended Laboratory Program” published by the College Board for AP classes. Please see
http://www.collegeboard.com/prod_downloads/ap/students/chemistry/ap03_chemistry.pdf
II. Performance or learner outcomes
Students will be able to perform accurate serial dilutions, calculate the molarity of solutions produced, standardize a Spec20 and analyze samples for dye concentration.
III. Resources, materials and supplies needed
Spec20, food colorings, volumetric pipets ( 5 mL, 10 mL, 25 mL and 50 mL), volumetric flasks (100 mL, 250 mL and 500 mL) , word processor and Excel. All glassware can be ordered from Fisher Scientific.
1 set of volumetric piptes and volumetric flasks per group of 4 students
Ideally 1 spectrophotometer per group of students.
IV. Supplementary materials, handouts .
Hand-outs, volumetric pipets ( 5 mL, 10 mL, 25 mL and 50 mL), volumetric flasks (100 mL, 250 mL and 500 mL), black rit dye.
Five-E Organization
Teacher Does Probing Questions Student Does
Engage: Learning Experience(s)
How do you think pharmaceutical companies make their own version of a competing product?
How do companies analyze the concentration of a component of a product? |
Critical questions that will establish prior knowledge and create a need to know
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Expected Student Responses/Misconceptions
Information freely given between companies or published somewhere.
Construct and use a calibration curve. |
Explore: Learning Experience(s) In groups of 3, students make 10 serial dilutions in a multi-well comibinatorics plate of a 10 % solution of Rit dye. A dropper will be used to add 1 drop of dye solution to a well and dilute with 9 drop of DI water.
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Critical questions that will allow you to decide whether students understand or are able to carry out the assigned task (formative)
How do you convert from % solution to molarity?
How do you calculate the molarity of the contents of each of the wells? |
Expected Student Responses/Misconceptions
Students may need help with Conversions; especially the conversion from % solution to molarity. |
Explain: Learning Experience(s)
2 groups will share their calculations and groups will reconcile sources of differences.
Team of 2 groups will prepare an explanation of their calculations on a big sheet of paper to share with the class.
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Critical questions that will allow you to help students clarify their understanding and introduce information related to concepts to be learned
Are the students performing the calculations correctly and are they able to explain their reasoning clearly.
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Expected Student Responses/Misconceptions
Groups of 3 are first formed to perform the dilutions and calculations. The (2) groups of 3 will be combined to compare calculations. After sources of discrepancies are resolved, a poster of calculations will be made. With this much self evaluation, the final calculations presented on the poster board will be nearly error proof. |
Extend / Elaborate: Learning Experience(s)
Students will be introduced to volumetric pipets volumetric flasks and their accuracy and proper use.
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Critical questions that will allow you to decide whether students can extend conceptual connections in new situations Can the students construct a scheme for making the dilutions to obtain solutions of specified concentration. |
Expected Student Responses/Misconceptions
Students will have trouble getting meniscus to calibration line on volumetric glassware.
Students will blow out remaining liquid on pipets calibrated TD. |
Evaluate: Lesson Objective(s) Learned (WRAP ≠UP at end) -> Summarize
In groups, students will formulate a plan to produce solutions of specified concentrations with volumetric glassware. Each group will hand in their dilution plan to obtain solutions of specified concentrations.
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Critical questions that will allow you to decide whether students understood main lesson objectives
Will dilution plans yield solutions of specified concentratons.
Are solutions made as efficiently as possible.
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Expected Student Responses/Misconceptions
Students will likely correctly plan dilutions. |
Percent effort each team member contributed to this lesson plan:
___%___ ____Name of group member_____________________
___%___ ____Name of group member_____________________