Mixtures & Solutions
Investigation 4
Part 2
Reaction Products
Students use filtering and evaporation as in previous investigations to separate and study the products of the chemical reactions they finished.
3. Lesson set up and Management
Physical and Chemical Changes (CH01 1.3.3)
- Know that matter can undergo changes of state such as evaporation, condensation, or freezing and thawing. Grades K, 1, 2, 3, 4, & 5.
- Understand physical and chemical changes at the particle level and know that matter is conserved. Grades 6, 7, & 8.
Planning and Conducting Investigations (IN02 2.1.2)
- Plan and conduct simple investigations, using appropriate tools, measures, and safety rules. Grades K, 1, 2, 3, 4, & 5.
- Plan, conduct, and evaluate scientific investigations, using appropriate equipment, mathematics, and safety procedures. Grades 6, 7, & 8.
Explaining (IN02 2.1.3)
- Use data to construct reasonable explanations. Grades K, 1, 2, 3, 4, & 5.
- Use evidence from scientific investigations to think critically and logically to develop descriptions, explanations, and predictions. Grades 6, 7, & 8.
- Precipitates can be formed in some chemical reactions.
- Some products of a reaction are soluble and can be observed only after the solution is evaporated.
3. Lesson set up and Management
Materials:
If you did not make a packet as mentioned in the FAQ section, copy Handout #16 for each student.
This lesson uses the evaporation trays again. Be sure all residues from the previous lessons are cleaned out of the dishes.
The filters will need a place to dry. Look for cheap cookie or cake racks; these are ideal to provide air circulation. They will dry on counters, just more slowly.
Student Management:
A verbal discussion on the methods for filtering, and a reminder on the use of evaporation trays, will help ensure success.
The discussion questions are important to help the students understand what is going on in the reactions. The background for the teacher section is well done and will help you with these explanations if it has been a long time since high school chemistry! The students find it interesting if you write the formulas for the chemicals on the board. This also allows you to show them where the sodium etc. comes from.
Writing Support:
Have the students complete Handout #16 to turn in for an assessment of their understanding. Also, have students answer the questions at the end of the reading selection in their journals.
Reading Support:
In the Mixtures and Solutions: Science Stories book, read "Ask a Chemist "and "The Periodic Table." There are several good videos on the periodic table; your district might have one. The students really like looking at posters of the periodic table and this is a great introduction to it.