Lesson Plan

# Concentrations

Students will conduct an investigation to verify that more concentrated solutions have more mass.
James M.
Classroom teacher
Boiling Springs Intermediate School
My Subjects Math, Science
Objectives

Students will be able to combine two substances (water and salt) to draw conclusions about the conservation of matter and the concentration comparisons of the three solutions created.

Subjects
Science

#### 1 Introduction

Activity: Presenting

1.  Distribute lab sheet - "Salt Concentrations"

Student Instructions

1.  In small groups, read and discuss the objective of the investigation.

2.  Summarize the objective and ask any questions.

#### 2 Direct Instruction

Activity: Presenting

1.  Display the investigation tools and explain how each should be utilized.   (graduated cylinders, graduated beakers, balances with holes on each end for the plastic cups to sit down inside, salt, measuring spoons, stir sticks)

Student Instructions

1.  Instruct students to return to group work areas and be called to the materials table for items.  Complete the investigation (Parts 1-3).

2.  Stop for discussion after making a prediction in Part 3, before comparing salt concentration #2 with salt concentration #3.

#### 3 Independent Practice

Activity: Investigating

1.  Collaborate and communicate while working through the lab sheet.

2.  Before completing Part 4, make a prediction about which salt solution is most concentrated - #2 or #3.

3.  After students make their predictions, have a discussion about how to make it a "Fair Test."  (Solution #3 was created using 150 mL of water.  Therefore, 100 mL of the solution will need to be poured out and used to compare with the 50 mL of solution #2 in order for it to be a fair test of salt concentration comparison).

Student Instructions

2.  Measure correctly - salt and water.  Check after each other and share the responsibilities.

3.  After making a prediction about which solution is most concentrated, STOP and discuss how to compare salt concentrations #2 and #3.  (the same amount of solution must be used for the comparison - 50 mL each)

#### 4 Wrap-Up

Activity: Assessing

1.  Clean up your station and put away materials.

2.  Record the answer to the final question:  Which salt solution was most concentrated?

3.  Bring closure to the investigation with a Kahoot created especially for this activity.

"Click" on the word "Kahoot" above to go to it.

Student Instructions

1.  Pick up, clean up, and record the discovery from the final salt solution comparison.  Students should clearly see that solution #2 was the most concentrated.  (50 mL of water mixed with 15 mL of salt)