DRAFT: This module has unpublished changes.

Methods:


  1.  Obtain about 20mL 6 M HCl stock solution. Pipet 16.5 mL of stock solution into a 1-L volumetric flask and fill the flask to the mark.  Mix the content of the volumetric flask and transfer the solution into a 1-L plastic bottle.  Label the bottle properly.
  2. Start a new experiment on the data collection system.
  3.  Connect the pH sensor and the Rotary Motion sensor to the data collection system.
  4. Set up Data Studio.
  5. Set up the Titrator pump.
  6. Rinse the syringe on the Titrator pump and set up the Titrator accessory.
  7. Calibrate the pH sensor.
  8. Add the micro stir bar to the end of the pH sensor.
  9. Setup the titrant container and replace the cap on the bottle, but not airtight.
  10. Load the syringe on the pump with the titrant solution.
  11. Prime the pump on the Titrator.
  12. Use the graduated pipet to transfer 20.00 mL of the HCl solution into a 180 mL titration jar and mount the jar on the Titration accessory over the magnetic stirrer.
  13. Add enough deionized water to the solution so the tip of the pH sensor is covered with solution.
  14. Turn on the magnetic stirrer at a steady rate.
  15. Start recording data.
  16. Press the "run" button on the Titrator to start the titration.
  17. Continue the titration past the equivalence point until the pH curve flattens.
  18. Stop recording data, and do the same for two more trials.
  19. Save experiment, clean the syringe on the Titrator, and clean up according to teacher's instructions.

Equipment:

  • Data collection system
  • pH sensor
  • Drop counter and micro stir bar
  • Magnetic stirrer
  • Buret, 50-mL
  • Graduated pipet with rubber bulb, 25-mL
  • Beaker, 100-mL (2)
  • Beaker, 25-mL (2)
  • Clamp,right-angle
  • Clamp, buret
  • Ring stand
  • Parafilm
  • Funnel
  • Hydrochloric Acid, unknown concentration, 70mL
  • Sodium hydroxide (NaOH), standardized by student in previous activity, 100mL
  • Buffers, pH 4 and pH 10, 10mL
  • Deionized water, 100mL
  • Wash bottle with deionized water
  • cotton swab or tissue
DRAFT: This module has unpublished changes.