| 1. |
Investigating Mixtures |
|
1-2 CLASS SESSIONS |
Students are introduced to the importance of water and to the SEPUP4-2-1 approach to group
interaction and individual responsibilities. Students then investigate the making of mixtures with a solid
and a liquid. Students learn that filtering is a way of separating undissolved substances from a liquid
based mixture. Students are then introduced to dissolved substances and the issue of wastewater disposal
and treatment.
|
| Concepts, Processes, Issues |
|
NSES 5-8 Content Standards |
| 1. |
Clean water is essential for life on earth. |
|
Perspectives: 1 |
| 2. |
Some substances dissolve in water, others do not. |
|
PhysSci: 1; EarthSci:1 |
| 3. |
Cooperative group work is an important component of scientific research. |
|
History: 1 |
| 4. |
A well-designed investigation tests only one variable. |
|
Inquiry: 1, 2 |
| 5. |
All matter is particulate in nature. |
|
PhysSci: 1 |
| 6. |
Filters can remove undissolved solid particles from a liquid.
|
|
PhysSci:1 |
| 2. |
Investigating Solutions |
|
1 CLASS SESSION |
Students further investigate solutions, with an emphasis on solubility as a property of
substances. Students operationally define solution, soluble, insoluble and saturated. Basic concepts of
the particle theory of matter are introduced.
|
| Concepts, Processes, Issues |
|
NSES 5-8 Content Standards |
| 1. |
A solution exists when one substance, the solute, dissolves in another, the solvent. |
|
PhysSci: 1 |
| 2. |
Solubility, the amount of a substance that can dissolve, varies from substance to substance. |
|
PhysSci: 1 |
| 3. |
A solution into which no more of a substance can be dissolved is a saturated solution. |
|
PhysSci: 1 |
| 4. |
Dissolved particles may or may not be detectable by sight; undissolved particles are visible.
|
|
PhysSci: 1 |
| 3. |
Reproducibility and Proper Use of Laboratory Equipment |
|
1 CLASS SESSION |
Students are introduced to the importance of consistent lab techniques and investigate reproducible
ways to use SEPUP dropper bottles and droppers. The emphasis in this activity is on the processes of investigation
using SEPUP materials.
|
| Concepts, Processes, Issues |
|
NSES 5-8 Content Standards |
| 1. |
A well-designed investigation tests only one variable. |
|
Inquiry: 1, 2 |
| 2. |
Standardizing laboratory techniques is essential for obtaining reproducible results.
|
|
Inquiry: 1 |
| 4. |
Comparing Solubility |
|
2-3 CLASS SESSIONS |
Students predict the solubility of several substances in water and alcohol. They then test
their predictions using a controlled experiment. Based on their results, they are introduced to the concept
of water as a “universal solvent.”
|
| Concepts, Processes, Issues |
|
NSES 5-8 Content Standards |
| 1. |
Water can dissolve many different solutes and is often called the “universal solvent.” |
|
PhysSci: 1 |
| 2. |
Water’s ability to dissolve many substances is both helpful and harmful to living organisms. |
|
Perspectives: 4 |
| 3. |
Industrial activity can introduce unwanted substances into the environment.
|
|
Perspectives: 1 |
| 5. |
Parts per Million |
|
2 CLASS SESSIONS |
In this activity, students explore the concept of one part per -(million, billion, or trillion)
and use if: as a measurement for the concentration of chemicals that are found in solutions. Students are
introduced to this concept through the process of serial dilution. Students learn how to quantify the concentration
of a solution in parts per million. The difference between an observation and an inference defined operationally.
|
| Concepts, Processes, Issues |
|
NSES 5-8 Content Standards |
| 1. |
There is variability in human response. |
|
LifeSci |
| 2. |
The concentration of a dissolved substance can be expressed in several different ways, including parts
per million (ppm) and parts per billion (ppb). |
|
Inquiry: 1, 2 |
| 3. |
Adding water to a solution dilutes the concentration of any dissolved substances and can change the
properties of the solution. |
|
PhySci: 1 |
| 4. |
The threshold level of a stimulus is the lowest level that provokes a response. |
|
LifeSci; Perspectives: 4 |
| 5. |
Decision-making involves evaluating trade-offs for different options.
|
|
Perspectives: 4, 5 |
| 6. |
Identifying Acid and Base Solutions |
|
2 CLASS SESSIONS |
Students explore the interactions among four different liquids (HCI, KOH, universal indicator,
and water). Operational definitions of acid, base and indicator are introduced. Students have further experiences
with variables and how to control them in an investigation. The knowledge about indicators is used to determine
whether the simulated industrial waste is acidic, basic or neutral.
|
| Concepts, Processes, Issues |
|
NSES 5-8 Content Standards |
| 1. |
All solutions can be classified as either acidic, basic, or neutral. |
|
PhysSci: 1 |
| 2. |
Acidic, basic and neutral solutions have different chemical properties which can be used to
differentiate
among them. |
|
PhySci: 1 |
| 3. |
Chemicals that change color in the presence of certain chemicals are called chemical indicators. |
|
PhySci: 1 |
| 4. |
Qualitative evidence and deductive reasoning can be used to make reasonable predictions
and to help
design investigations.
|
|
Inquiry: 1, 2; History: 1 |
| 7. |
Diluting Acids and Bases |
|
2 CLASS SESSIONS |
Students observe the change in the color of universal indicator in an acid or a base as
the solution becomes more dilute. They continue the development of the operational definitions of acids,
bases, and indicators. Students know that the simulated wastewater contains acid. They are asked to consider
the trade-offs involved in using dilution to prevent the pollution of a lake by industrial waste.
|
| Concepts, Processes, Issues |
|
NSES 5-8 Content Standards |
| 1. |
Adding water to a solution dilutes the concentration of any dissolved substances and can change the
properties of the solution. |
|
PhysSci: 1 |
| 2. |
As the concentration of an acidic or basic solution lowers, the properties of the solution become increasingly
similar to water. |
|
PhysSci: 1 |
| 3. |
The pH scale classifies the relative acidity/basicity of a solution. |
|
PhysSci: 1 |
| 4. |
A solution’s pH affects how that solution will react with other substances and living organisms.
|
|
PhysSci: 1 |
| 8. |
Acid-Base Neutralization |
|
2-4 CLASS SESSIONS |
Students use pH indicators to investigate the effect on pH of various ratios of 0.1% HCI
and 0.1% KOH. Students are introduced to the concept of neutralization and then go on to explore it quantitatively.
They determine the ratio of the O.1% HCI and 0.1% KOH solutions that must be mixed to produce a neutral
solution. Their results are used to reinforce the particulate nature of matter. Students then use a particle
model to further explore concentration and explain neutralization.
|
| Concepts, Processes, Issues |
|
NSES 5-8 Content Standards |
| 1. |
Combining an acid with a base produces a chemical reaction that results in a solution with an intermediate
pH. |
|
PhysSci: 1 |
| 2. |
If combined in a specific ratio, any acid and base combination can produce a neutral solution. |
|
PhysSci: 1 |
| 3. |
Acids and bases neutralize each other on a one-to-one particle basis. |
|
PhysSci: 1 |
| 4. |
Neutralization reactions can be used to treat non-neutral wastewater.
|
|
PhysSci: 1; SciTech;
Perspectives |
| 9. |
Removing Dissolved Substances from a Solution |
|
2 CLASS SESSIONS |
Students explore the use of chemical reactions that produce precipitates as a means of removing
dissolved substances from a solution. Students investigate the formation of an insoluble precipitate when
two solutions are mixed and the separation of the precipitate from the liquid by filtration. This process
is then evaluated as a possible method for cleaning the simulated industrial wastewater.
|
| Concepts, Processes, Issues |
|
NSES 5-8 Content Standards |
| 1. |
Chemical reactions often cause easily observable changes. |
|
PhysSci: 1, 3 |
| 2. |
When a chemical reaction produces an insoluble product, the product appears as a precipitate. |
|
PhysSci: 1 |
| 3. |
Filters can remove undissolved solid particles from a liquid. |
|
PhysSci: 1 |
| 4. |
Chemical reactions can be described by chemical equations. |
|
PhysSci: 1 |
| 5. |
Chemicals react with each other on a one-to-one particle basis. |
|
PhysSci: 1 |
| 6. |
Precipitation reactions can be used to treat wastewater containing dissolved substances.
|
|
PhysSci: 1; SciTech;
Perspectives |
| 10. |
Treating the Acme Wastewater |
|
2 CLASS SESSIONS |
Students use the knowledge and understandings developed in this module to plan and carry
out an investigation that will help them decide which method is most acceptable for treating the simulated
industrial wastewater.
|
| Concepts, Processes, Issues |
|
NSES 5-8 Content Standards |
| 1. |
A technological solution to a problem can be tested and revised through experimentation. |
|
SciTech: 1, 2 |
| 2. |
Perfectly designed solutions do not exist; all solutions have trade-offs.
|
|
SciTech: 1, 2 |
