Cell Biology: Diffusion

Explore the movement of molecules via diffusion and determine how temperature affects the rate of diffusion.

Lab Summary:

In this exploration, students will explore the process of diffusion using a pH Sensor. By measuring the change in pH as ions diffuse into a solution, students will determine that ions move from an area of higher concentration to a less concentrated area, until a state of equilibrium is reached. In addition, students will study how temperature affects the rate of diffusion.

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(student version)

Method:

Use a pH Sensor to study the process of diffusion.

Here's What You Need:

Probeware

• PASPORT pH Sensor (PS-2102)
• PASPORT Temperature Sensor (PS-2125)
• Xplorer GLX Graphing Datalogger (PS-2002)
  (or alternate PASPORT interface -- see other options)

Other Materials

• Clamp, Buret (2) (SE-9446)
• Clamp, Three-Finger (SE-9445)
• Small Base & Support Rod (2) (SE-9451)
• Test tube, Medium
• Beaker, 500-mL
• Hot plate
• Wash bottle
• Waste container
• Pipet with bulb
• Kimwipes or paper towels
• Water, Distilled, 1.0 L
• Water, 450.0 mL
• Ammonia, 5.0 mL

Lab Manual:

This activity is included in Explorations in Biology (PS-2807), complete with Teacher Information pages, student instructions and handouts, and sample data for a total of 25 probeware-based labs. For your convenience, we offer bundles which provide the probeware necessary for the activities in the manual. For more information on these resources and bundles, click here.