Quantities and Reactions : Buffers

Determine the effect of a strong acid and a strong base on the pH of water and the pH of a buffer solution to develop an understanding of buffering and of chemical equilibrium.

Lab Summary:

Students will measure the pH effects of a strong acid (hydrochloric acid) and of a strong base (sodium hydroxide) on pure water. They will then repeat the procedure using an acetic acid/sodium acetate solution, exploring the solution's ability to maintain pH.

Download Free Lab  (PDF, 184 KB)

(student version)

Method:

In this exploration students will measure pH changes with the Chemistry Sensor to observe the change in pH as they add strong acids or strong bases to pure water and to a buffer solution.

Here's What You Need:

Probeware

• PASPORT Chemistry Sensor (PS-2170)
• Xplorer GLX Graphing Datalogger (PS-2002)
  (or alternate PASPORT interface -- see other options)

Other Materials

• Beakers, 50 mL (3)
• Graduated cylinder, 100 mL
• Stirring rod
• Eye dropper or pipet
• 0.1 M acetic acid (CH₃CO₂H)
• 1.0 M hydrochloric acid (HCl)
• 0.1 M sodium acetate (CH₃CO₂Na)
• 1.0 M sodium hydroxide (NaOH)
• Water

Lab Manual:

This activity is included in Chemistry with the Xplorer GLX (PS-2819A), complete with Teacher Information pages, student instructions and handouts, and sample data for a total of 19 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.