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Invitation/Fundamental Understandings:
Essential
Questions:
Knowledge and skills: Fundamental
Understandings:
Stoichiometry allows us to determine
mathematically and measure how much of a product is made from a
specific amount of raw materials or how much raw materials are
needed to make a chemical product.
Essential Questions:
1. Is
there more than one "recipe" or quantity for making
something? Explain your answer.
2. Is there more than 1
technique to making a product? Explain.
3. Would it be truly
economical to always purchase a generic product over a name
brand? Defend your answer.
4. Why might one not get 100% yield?
Are there specific factors that cause this?
Knowledge and Skills:
1. Be able to write a formula for a compound or
element.
2. Determine the type of compound or element used in a
reaction
(ionic, molecular, organic, acid, etc)
3. Have
knowledge of the Law of Conservation of Matter
4. Be able to
write and balance a chemical equation.
5. Determine the type of
reaction involved in the making of a product
6. Determine
mole ratios from a balanced equation
7. Employ stoichiometric
techniques to solve the problem of "how much..."
8. Calculate
the percent yield from theoretical and experimental data.
Standards
National Standards UNDERSTANDINGS ABOUT
SCIENTIFIC INQUIRY
Scientists usually inquire about how
physical, living, or designed systems function. Conceptual
principles and knowledge guide scientific inquiries. Historical and
current scientific knowledge influence the design
and
interpretation of investigations and the evaluation of
proposed explanations made by other scientists.
Scientists
conduct investigations for a wide variety of reasons. For example,
they may wish to discover new aspects of the natural world, explain
recently observed phenomena, or test the conclusions of prior
investigations or the predictions of current theories.
Scientists rely on technology to enhance the gathering and
manipulation of data. New techniques and tools provide new evidence
to guide inquiry and new methods to gather data, thereby
contributing to the advance of science. The accuracy and precision
of the data, and therefore the quality of the exploration, depends
on the technology used
Mathematics is essential in
scientific inquiry. Mathematical tools and models guide and improve
the posing of questions, gathering data, constructing explanations
and communicating results.
Scientific explanations must
adhere to criteria such as: a proposed explanation must be logically
consistent; it must abide by the rules of evidence; it must be open
to questions and possible modification; and it must be based on
historical and current scientific knowledge.
Results of
scientific inquiry--new knowledge and methods--emerge from different
types of investigations and public communication among scientists.
In communicating and defending the results of scientific inquiry,
arguments must be logical and demonstrate connections between
natural phenomena, investigations, and the historical body of
scientific knowledge. In addition, the methods and procedures that
scientists used to obtain evidence must be clearly reported to
enhance opportunities for further investigation.
Technology
Standard(s):
Standard 4: Technology Communication
Tools
Students use telecommunications to collaborate, publish and
interact with peers, experts and other audiences
Standard 5:
Technology Research Tools
Students use technology tools to
process data and report results
Information Literacy
Standard(s):
Standard 1: The student who is information literate
accesses information efficiently and effectively
Standard 2: The
student who is information literate evaluates information critically
and competently
Standard 3: The student who is information
literate uses information accurately and creatively
State Standards Nebraska: 12.2.1 By the
end of twelfth grade, students will develop the abilities needed to
do scientific inquiry.
Nevada: Scientific Inquiry: Processes and
Skills 20.0 Students understand that a variety of models can be used
to describe or predict things and events 21.0 Students understand
that science is an active process of systematically examining the
natural world 22.0 Students understand that a variety of
communication methods can be used to share scientific information
23.0 Students understand that scientific inquiry is enhanced and
often communicated by using mathematics 24.0 Students can
appropriately and safety apply the tools and techniques of
scientific inquiry
Workforce Competencies: Resources -
Identifies, organizes, plans, and allocates resources C. Material
--Acquires, stores, allocates, and uses materials efficiently
Interpersonal: Works with others A. Participates as Member of a
Team--contributes to group effort Information: Acquires and uses
information A. Acquires and Evaluates Information B. Organizes and
Maintains Information C. Interprets and Communicates Information D.
Uses Computers to Process Information
Unit of Practice
Relevance:
Stoichiometry deals with one of the four fundamental questions of
chemistry: How Much? This has value in industry, which needs to know
how much raw material to order to make such things as automobiles,
cloth, plasticware, prescription drugs, etc. It also helps to
predict how much waste products are generated, such as automobile
exhaust in large cities, smokestack pollution and effluents. On an
individual scale, a kitchen recipe is a stoichiometric process and
when a person doubles or halves the recipe he/she is performing
stoiciometry.
Context
Prior to the unit students can perform the following content area
skills: 1. naming compounds and writing formulas 2. writing and
balancing equations 3. determining molar mass of compounds 4.
converting grams to moles and moles to grams Prior to the unit,
students have the following laboratory skills: 1. massing chemicals
with proper significant figures 2. using measuring tools such as
graduated cylinders and graduated pipets, with proper significant
figures 3. use of Bunsen burner and crucibles 4. use of thermometers
5. be familiar with basic safety rules and procedures Prior to the
unit students have acquired the following information and technology
skills: 1. presentation skills 2. desktop publishing skills 3.
internet research skills
Assessment
Formative Assessment
1. Journal entries for each step of
project
2. Reports for each step of project
3. Independent
practice. Group and homework assignments
4. Lab reports for
Exploration and Application labs
5. Peer grading
6.
Traditional quizzes
Summative Assessment
1. Make a
specific amount of product from specific amounts of raw materials.
Students must determine amounts to use and prepare a final report.
Products made may include:
a. Personal grooming materials such as
soap, shampoo, skin cream and detergent
b. Polymers such as glue,
GAK, super balls and slime
c. Energy emitting materials such as
luminescent wands and paper, cold packs and hot packs
d. Metal
plating (silver and copper) of objects
e. Photographs
2.
Make a formal presentation to the class (See Lesson 8)
3. Compare
and contrast different "brands" of product and analyze differences
using qualities defined by students. Draw conclusions and write a
report. Class sharing of reports.
4. Traditional unit
test
Components:
Lesson 1: Introduction to Stoichiometry: The Mole Ratio *Demo: 5
pennies, 1 nickel Mass ratio vs. value ratio *Discuss the analogy:
How does this relate to mole ratio and mass ratio *Teacher
definition and guided practice of mole ratio *Independent practice
with group feedback *Homework: mole-mole problems *Exploration Lab:
Hydrochloric Acid and Sodium Carbonate (for example, see "Totally up
Front" in CRYSTAL)
Lesson 2: Introduction to Project: Origins and
History (Step 1 Worksheet) *Hand out Project Description *Partner
assignment/selection and assignment/selection of product *Class
Discussion of Project, expectations and timeline *On-Line research
of product origin, history and qualities of product
Lesson 3:
Research Reactants and Products (Step 2 Worksheet) *Hand out student
"recipe" for product, which contain no specific amounts of reactants
*Research Physical and Chemical Characteristics of reactants and
products *Research Safety Considerations of materials and procedure
*Review and refine desired qualities of product
Lesson 4: Analyze
Product Recipe (Step 3 Worksheet) *Write and balance chemical
reaction involved in production of product *Determine type of
chemical reaction involved *Determine by-products (if any) and
potential hazards *Review and refine desired qualities of product
*Devise ways to "test" qualities
Lesson 5: Techniques of
Stiochiometry (Step 4 and 5 Worksheet) *Review moles--> grams and
grams --> moles problems *Create class "roadmap" for
stoichiometry problems (See attached brainstorming diagram for
board) *Teacher definition and guided practice of grams--> grams
stoichiometry problems *Independent practice with group feedback
*Homework: Mixed-stoichiometry problems *Application Lab:
Stoichiometry Lab (for example, see "Bicarbonate Dilemma" in
CRYSTAL) *QUIZ – mixed stoichiometry problems *Project Trials –
Determine final recipe for product by doing 3 trials, with
evaluations between each trial
Lesson 6: Limiting Reactants/ Percent
Yield (Step 6 Worksheet) *Class Activity: How Many Burritos can you
make? (Handout) *Teacher definition and guided practice of limiting
reactants and percent yield *Independent practice with group
feedback *Homework: Independent Practice homework *Application Lab:
Lab using limiting reactants or percent yield skills (for example,
see "The Case of the Adulterated Baking Soda" in CRYSTAL) *Class
Activity - Example: Paint company making glow-in-the-dark signs with
a color that is added as a concentrate with a percent yield ;
students must determine how much of concentrate to add to make a
specific amount of paint. *Project Trials – By determining the %
yield from initial trial data, students will Determine the amount of
reactants needed to make enough product for classes, then perform 2
additional trials to obtain that amount. Turn in amount needed to
share with other classes.
Lesson 7: Presentation, Testing and
Evaluation (Steps 7 and 8 Worksheet) *Traditional Unit test *Formal
Presentation to Class of Product - Students must explain their
scientific process, the qualities of their product, the problems
they encountered and the resolution of those problems *Evaluation of
Products - Using qualities defined by students, compare and contrast
products from other classes/schools. If other schools are involved,
the report should be shared over the internet . *Discussion of
Reports and feedback with other schools, if applicable
Additional Resources
Main
URL:
Related Resources
Related Lessons
Copyright © 1997-2003
Career Connection to Teaching with Technology
USDOE Technology Innovation Challenge Grant
Marshall Ransom, Project Manager
All rights reserved.
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