Description:

Overall Task Content Area:

Physical Science

Specific Knowledge Areas:

Properties and changes in properties of materials

Performance Expectations:

• 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 Educational Standards

8 A SI 1: Abilities Necessary to do Scientific Inquiry: Grades 5-8
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.

8 B PS 1: Properties and changes of properties in matter: Grades 5-8
1.1 A substance has characteristic properties, such as density, a boiling point, and solubility, all of which are independent of the amount of the sample. A mixture of substances often can be separated into the original substances using one or more of the characteristic properties.

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

General Instructions for the Teacher:

• Students need to be ready to work as soon as the period begins.
  
  
• Group assignments should be made in advance.
  
  
• The materials should be set out at each lab station, if possible.
  
  
• A central supply area, if needed, should be easily accessible.
  
  
• The supply area should have any supplies from the kit that were prepared by the teacher as well as all of the school-supplied materials necessary for the experiment.
  
  
• All the supplies should be clearly labeled.
  
  

Materials for "pH Acid Base Indicators":

Per class - (5 groups)


• 25 strips pH paper
• 5 pH color charts
• 45 cups
• 25 pair plastic gloves
• 5 markers
• 1 25 ml squeeze bottle of each of the following
  
  • dilute acid, labeled A
  • dilute base, labeled B
  • seltzer water, labeled C
  • 10% borox solution, labeled D
  • distilled water, labeled as such
  • lemon juice, labeled as such
  • vinegar, labeled as such
  • liquid soap, labeled as such
  • NaOH, labeled as such
• 1 50 ml squeeze bottle of Universal Indicator
• paper towels
• tap water
• safety goggles
• lab aprons
• 1 pen or pencil per student

Advance Preparation:

• a pH paper color chart;
• 5 strips of pH paper;
• 9 plastic cups;
• 5 pair of plastic gloves; and
• 1 laboratory marker.

Each student group will obtain their solutions from the containers in the central supply area. We recommend that students wear goggles, aprons, and plastic gloves while collecting the data.

Safety:

• 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.