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Lecture Room Size pH Meter


Large Display

Old Style pH Meter with "Recorder Out" plugs and pH Electrode

3V Step-up Voltage box with red and back leads in and out

pH 7 and pH 10 buffers

250 mL (or larger) Beaker

Magnetic Stir Bar

Magnetic Stir Plate

0.1M Hydrochloric Acid

0.1M Sodium Hydroxide

Bottle of DI water

25 mL Graduated Cylinder

Phenolphthalein Indicator

Buret on a ring stand

Funnel with a tip that fits inside the buret (for filling Buret)

Gloves and Goggles



  • From the recorder output of the pH meter, plug in leads running to the mini-amp "millivolts in" plugs.
  • From the "0 to 3 out" plugs, run leads to the "U" input plugs on the base unit. Be sure the 3V module is in place. Careful not to cross the "+" and "-" leads.
  • Settings on the base unit are center zero and direct current (bottom front right corner).
  • Both the mini-amp and base unit must be turned on.
  • In a 250ml beaker, add 25ml acid, 25ml water, a stir bar, and two drops of phenolphthalein indicator.
  • Place beaker on a stir motor and mount the buret and electrode in appropriate positions; check to be sure that the electrode cannot be damaged by the stirring bar.
  • Fill the buret with sodium hydroxide solution and titrate. The acid and base solutions are equimolar.

Waste Management

Solutions from this demonstration can be neutralized and poured down the sink.