Titration Technique Lecture Notes

Presenter Information

• Presenter: Jared Hyman
• Position: Assistant Professor of Chemistry
• Affiliation: Elon University

Lecture Overview

• Main Topic: Proper titration technique.
• Series: Part 1 of a two-part series.
• Purpose of Titration: To quantitatively determine the concentration of an unknown solution (analyte) by adding a known concentration of another chemical (titrant).

Equipment Needed

• Burette Assembly: Available from Carolina's Biological Supply Company.
  • Contains a burette, ring stand, and burette clamp.
  • Burette: Long, narrow, graduated tube with a stopcock.
    • Markings: Lowest at top, highest at bottom.
    • Function: Regulates liquid flow.
  • Ring Stand and Clamp: Used to secure the burette.
• Additional Materials:
  • Small funnel
  • 125 ml Erlenmeyer flask
  • Volumetric pipette and pipette bulb
  • Wash bottle with deionized water
  • Beaker/flask of titrant and analyte
  • Selected indicators
  • Reading card and white paper

Preparing the Burette

• Rinsing:
  • Rinse with deionized water, then with a small amount of titrant.
  • Open stopcock after each rinse to drain.
• Cleaning:
  • Clean burette thoroughly if liquid clings to walls.
• Mounting:
  • Ensure burette is vertical and flask fits underneath.

Filling the Burette

• Insert funnel and fill with titrant, not necessarily to the zero mark.
• Check for air bubbles, remove them by tapping.
• Allow a few milliliters of titrant to release through the stopcock.
• Rinse tip and flask, no drying needed.

Reading the Volume

• Meniscus:
  • Read from the bottom at eye level.
• Significant Figures:
  • Burette reads to nearest 0.1 ml.
  • Record to nearest 0.01 ml.

Performing the Titration

• Transferring Analyte: Use a volumetric pipette.
• Adding Indicator: Add drops and swirl.
• Initial Titration:
  • Estimate the endpoint by allowing titrant to flow quickly.
  • Record initial and final volumes to estimate needed titrant.
• Endpoint Adjustment:
  • Adjust for a faintly colored analyte.
  • Slow titrant addition near endpoint.
  • Rinse, swirl, and record until endpoint is maintained.

Final Steps

• Triplicate Titration:
  • Perform three times and average results.
• Calculations: Use average volume for concentration calculations.

Preview of Next Lecture

• Topic: Determining concentration of an unknown acid using a known base.
• Products: Available at Carolina Chemistry's website.

This concludes the notes on part one of the titration series. Ensure to view the next session for further understanding.