How Can You Speed Up Mixing?
Summary
In this classroom activity, students investigate mixtures and how they are formed. They predict which factors will increase the rate of mixing a sugar cube and a 1/2 cup of water. Students will work in teams and complete an activity sheet based on the OWL (Observation, Wondering, Learned) structure.
CollapseLearning Goals
1. Observation: Students will observe the control. They will analyze the cube dissolving in the water.
2. Predictions: Students will make predictions about the length of time it will take to dissolve without handling the sugar/water mixture. They will then create questions about decreasing the time it takes to dissolve the cube.
3. Learned: Students will summarize their findings in a table and agree upon their best method.
Students will also work on communication, data recording, cooperation, measuring, questioning.
Vocabulary terms include solvent, solute, mixture, solution, and dissolve.
2. Predictions: Students will make predictions about the length of time it will take to dissolve without handling the sugar/water mixture. They will then create questions about decreasing the time it takes to dissolve the cube.
3. Learned: Students will summarize their findings in a table and agree upon their best method.
Students will also work on communication, data recording, cooperation, measuring, questioning.
Vocabulary terms include solvent, solute, mixture, solution, and dissolve.
Context for Use
This lesson is appropriate when students are learning about mixtures. I assume it could be taught in a 30-40 minute block of time. Discussion of the control or the conclusion could be done on separate days to give kids more time to explore. Students will have had a lesson in changes of state prior to this lesson. It is easy to adapt to any setting.
Description and Teaching Materials
1. Students are placed in groups and cooperatively choose job assignments as listed on Activity sheet.
2. Each group has a glass container, 1/2 cup water and 1 whole sugar cube. Time is noted and students are directed to observe cube as it dissolves in cup. Kids should not manipulate jar. Lead discussion regarding this Observation section of their activity sheet.
3. Ask like to predict how long it will take to completely dissolve this cube in this manner.
4. Tell them that they will be conducting an experiment today using these same materials. Ask them to think of what methods will work best to decrease dissolving time. This is the Wondering section of their papers.
5. Explain that they will have the following materials available to them: sugar cubes, water, glassware, measuring cups, stopwatches, spoons, safety glasses, various kitchen gadgets - graters, garlic press, chopsticks, and straws to use.
6. They must prepare a chart during their experimenting.
7. They may do experiments simultaneously as long as they are recording data.
8. After most students have had an opportunity to complete experiments, discuss the "Learned" section on their papers.
9. Watch You Tube video clips for closure and assessment. Observe and discuss the dissolving under the microscope and predict how the boy dissolved his cube so quickly. Mixtures Activity Handout (Microsoft Word 281kB Aug3 09)
2. Each group has a glass container, 1/2 cup water and 1 whole sugar cube. Time is noted and students are directed to observe cube as it dissolves in cup. Kids should not manipulate jar. Lead discussion regarding this Observation section of their activity sheet.
3. Ask like to predict how long it will take to completely dissolve this cube in this manner.
4. Tell them that they will be conducting an experiment today using these same materials. Ask them to think of what methods will work best to decrease dissolving time. This is the Wondering section of their papers.
5. Explain that they will have the following materials available to them: sugar cubes, water, glassware, measuring cups, stopwatches, spoons, safety glasses, various kitchen gadgets - graters, garlic press, chopsticks, and straws to use.
6. They must prepare a chart during their experimenting.
7. They may do experiments simultaneously as long as they are recording data.
8. After most students have had an opportunity to complete experiments, discuss the "Learned" section on their papers.
9. Watch You Tube video clips for closure and assessment. Observe and discuss the dissolving under the microscope and predict how the boy dissolved his cube so quickly. Mixtures Activity Handout (Microsoft Word 281kB Aug3 09)
Teaching Notes and Tips
I used the control as my lesson observation. It takes 20 minutes or so for this sugar to dissolve so start early and remind students to record times on their chart.
Assessment
This will be assessed informally. A copy of their activity sheet will be collected. Students should conclude that stirring crushed sugar in heated water will indicate the shortest mixing time.
There are also two fun YouTube videos. The first is a 32 second clip of a granule of sugar dissolving under a microscope. The second is a clip called "Solute and Solvent". Kids can predict what method the boy used to dissolve the sugar in his video.
There are also two fun YouTube videos. The first is a 32 second clip of a granule of sugar dissolving under a microscope. The second is a clip called "Solute and Solvent". Kids can predict what method the boy used to dissolve the sugar in his video.
Standards
5.1.1.2.1 Generate a scientific question and plan an appropriate scientific investigation, such as systematic observations, field studies, open-ended explorations or controlled experiments to answer the question.