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Acids and Bases -- Vinegar I
Administration Procedures

8th Grade Performance Task
Contributed by: RAND
Designed by: University of California, Santa Barbara, Stanford University, and The Far West Laboratory

Description:

In the first part of Acids and Bases - Vinegar, entitled "Discovery," students will design and perform an experiment. Students will use a Universal Indicator Color Guide to measure the strength of acids and bases, as well as what happens when acids and bases are mixed together. Additionally, students decide which of three solutions of unknown pH will neutralize a fourth solution of unknown pH. Students have to apply this process to a problem involving a vinegar and an unknown vinegar solution.

This task assesses students' abilities to provide independent variables, draw diagrams, design and conduct an experiment, collect, organize and present data, and draw conclusions about the experiment and the relationship found.

Overall Task Content Area:

Physical Science

Specific Knowledge Areas:

Properties and changes of properties in matter
 

Performance Expectations:

  • designing and conducting investigations
  • using equipment
  • gathering, organizing, and representing data
  • formulating conclusions from investigational data
  • applying scientific principles to develop explanations and solve new problems

National Science Education Standards:

8 B PS 1: Properties and changes of properties in matter: Grades 5-8
1.2 Substances react chemically in characteristic ways with other substances to form new substances (compounds) with different characteristic properties. In chemical reactions, the total mass is conserved. Substances often are placed in categories or groups if they react in similar ways; metals is an example of such a group.

8 A SI 1: Abilities necessary to do scientific inquiry: Grades 5-8
1.2 Design and conduct a scientific investigation. Students should develop general abilities, such as systematic observation, making accurate measurements, and identifying and controlling variables. They should also develop the ability to clarify their ideas that are influencing and guiding the inquiry, and to understand how those ideas compare with current scientific knowledge. Students can learn to formulate questions, design investigations, execute investigations, interpret data, use evidence to generate explanations, propose alternative explanations, and critique explanations and procedures.

1.3 Use appropriate tools and techniques to gather, analyze, and interpret data. The use of tools and techniques, including mathematics, will be guided by the question asked and the investigations students design. The use of computers for the collection, summary, and display of evidence is part of this standard. Students should be able to access, gather, store, retrieve, and organize data, using hardware and software designed for these purposes.

1.4 Develop descriptions, explanations, predictions, and models using evidence. Students should base their explanation on what they observed, and as they develop cognitive skills, they should be able to differentiate explanation from description — providing causes for effects and establishing relationships based on evidence and logical argument. This standards requires a subject knowledge base so the students can effectively conduct investigations, because developing explanations establishes connections between the content of science and the contexts within which students develop new knowledge.

(Use the "hot" link on the PALS home page to check the full text of related National Science Education Standards, if desired.)

General Instructions to the Teacher:

Students will be working individually for the experiment/activity part of this exercise.

The materials should be set out at each lab station, if possible. A central supply area, if needed, should be easily accessible. All supplies should be clearly labeled.

Materials:

At each station students will need:

  • 1 bottle labeled INDICATOR
  • 1 bottle labeled BASE X
  • 1 bottle labeled ACID A
  • 1 bottle labeled ACID B
  • 1 bottle labeled ACID C
  • 3 plastic cups
  • 1 placemat
  • Safety goggles
  • Paper towels for spills

Advance Preparation:

SOLUTION CONCENTRATIONS
FOR
ACIDS AND BASES VINEGAR

Indicator 50% Lab-Aids Universal Indicator and 50% deionized water
Base X 1.5. ml 5% ammonia and 8.5 ml deionized water
Acid A 4 ml 5% vinegar and 6 ml deionized water
Acid B

5% vinegar solution
Acid C 4 ml 5% vinegar and 6 ml deionized water

 

Safety:

  • Wear Goggles.
  • Be careful.
  • Teachers and students should always exercise appropriate safety precautions and utilize appropriate laboratory safety procedures and equipment when working on science performance tasks.

Extensions and Modifications:

Acids and Bases Vinegar II and III

 

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