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Session 1: How can we purify our water?
Dissolved substances in natural waters and their sources; concentration
units; bar diagrams.
Exploration 1A: The Storyline
Exploration 1B: What substances do you typically find in natural waters?
Exploration 1C: How do dissolved substances get into a water supply?
Exploration 1D: How can we obtain a quantitative profile of the ionic constituents
in a water supply?
Session 2: How do you determine how much of a constituent
is in a water supply?
Analytical methods for fluoride (ion-selective electrode); water
hardness (EDTA titration); iron (colorimetric method); total alkalinity (acid-base
titration); total dissolved solids (conductimetric or gravimetric).
Exploration 2A: The Storyline
Exploration 2B: How do you determine how much fluoride is in a water supply?
Exploration 2C: How do you determine how much calcium and magnesium is in
a water supply?
Exploration 2D: How do you determine how much iron is in a water supply"
Exploration 2E: How do you determine the total alkalinity in a water supply?
Exploration 2F: How do you determine the concentration of Total Dissolved
Solids in a water supply?
Session 3: Why do substances dissolve in water?
Polarity; solubility of organic and inorganic constituents in
water; thermodynamics of the dissolution process.
Exploration 3A: The Storyline
Exploration 3B: What do we mean by the word "dissolve"?
Exploration 3C: What characteristics of a substance affect its solubility in water?
Session 4: How can we best describe the extent of a chemical
reaction?
Introduction to equilibrium; dynamic nature of equilibrium;
equilibrium expressions and calculations; the reaction quotient, Q; solubility
product constant, Ksp; and the relationship of the equilibrium constant to
free energy.
Exploration 4A: The Storyline
Exploration 4B: What is equilibrium?
Exploration 4C: What does a chemical system at equilibrium look like at
the microscopic level?
Equilibrium Simulator (with reaction probabilities)
Equilibrium Simulator (with equilibrium
constant)
Exploration 4D: How can equilibrium reactions be described mathematically?
Exploration 4E: How can we use the equilibrium expression to predict equilibrium
concentrations?
Exploration 4F: How can you tell whether a reaction has reached equilibrium?
Exploration 4G: How is free energy related to the extent of a reaction?
Session 5: How can we remove contaminants from a water
supply?
Le Chatelier's principle and the effects of concentration, temperature,
and pressure on the position of an equilibrium; common ion effect.
Exploration 5A: The Storyline
Exploration 5B: How can we drive an equilibrium reaction to one side?
Exploration 5C: Which precipitating reagent will remove the most contaminant?
Exploration 5D: How much precipitating reagent is required for effective
water treatment?
Session 6: What procedures can you design to remove contaminants
from a water supply?
Applying the principles of equilibrium and precipitation to
remove contaminants from a water sample.
Exploration 6A: The Storyline
Exploration 6B: How can excess fluoride be removed from a water supply?
Exploration 6C: How can excess water hardness be removed from a water supply?
Exploration 6D: How can excess iron be removed from a water supply?
Session 7: What are acids and bases?
Definitions of acids and bases and their relative strengths;
the pH scale; calculations involving strong and weak acids and bases; relationship
of acid strength to structure and composition of the acid; thermodynamics
of acid-base reactions.
Exploration 7A: The Storyline
Exploration 7B: How are acid and base strengths correlated to the extent
of the acid-base reaction?
Exploration 7C: How can we best quantify acid and base concentrations?
Exploration 7D: How do you determine equilibrium concentrations of strong
and weak acids and bases?
Exploration 7E: How is acid strength related to the structure and composition
of the acid?
Session 8: What is the role of acids and bases in water
treatment?
Effects of pH on solubility; neutralization reactions; analytical
method for measuring pH.
Exploration 8A: The Storyline
Exploration 8B: How can we selectively remove ions from solution?
Exploration 8C: How do you measure the pH of a water supply?
Exploration 8D: How do you change the pH of a water supply?
Session 9: What are your results?
Projects
Project 1: Poster Presentation
Project 2: Scientific Report
Project 3: Community Education