DRAFT: This module has unpublished changes.

Equipment:

  • Data Collection System
  • pH Sensor
  • Magnetic Stirrer
  • Ring Stand
  • Beaker (2), 100-mL
  • Beaker (2), 10-mL
  • Volumetric Flask, 1000-mL
  • Erlenmeyer Flask, 250-mL
  • Hot Plate/Magnetic Plate
  • Automatic Titrator
  • Funnel
  • Jar with custom-made hockey puck-derived lid, 180-mL
  • Hydrochloric Acid, unknown concentration (approximately 6M), 70 mL
  • Sodium Hydroxide (NaOH) solution, standardized in Lab 6a, 100 mL
  • Buffers, pH 4 and pH 10, 10 mL
  • Water, deionized, 100 mL
  • Plastic Bottle, 1-L
  • Wash Bottle
  • Pipet
  • Aluminum Foil
  • Tissue

Method:

  • Gathered all equipment and materials. Inspected all equipment for damage or contamination. Hotplate/Magnetic Plate and Stand were already assembled.
  • Obtained 20 mL of 6 M HCL stock solution. Pipetted 16.5 of the stock solution into a 1000 mL volumetric flask, and diluted solution to 1 L with deionized water.
  • Sealed flask, inverted flask, shook gently to stir. Vented flask once solution had become homogenous. Transfered solution to 1 L plastic bottle. Labeled bottle.
  • Started a new experiment with the data collection system. Set up graph.
  • Set up the Titrator, flushing it once with deionized water.
  • Calibrated the pH sensor, by rinsing it, measuring the pH of the buffer solutions, taking care to rinse the sensor between measurements, and then testing it with the buffers again.
  • Added the magnetic stirrer to the end of the pH sensor, and passed it through the hockey-puck lid, and into the jar, ensuring that the entire apparatus was secured to the stand.
  • Transferred, via pipet, 20 mL of the HCl solution to the 180 mL jar, and attaching it to the hockey puck lid. Ensured that the pH sensor was submerged within the solution 
  • Loaded the Titrator with the NaOH titrant that was standardized in Lab 6a.
  • Activated magnetic stirrer, and set to a mid-range speed.
  • Activated the Titrator, running beyond the equilibrium point, until the pH curve had flattened, ensuring that the system was recording at the time.
  • Repeated with a second and third HCl solution.
  • Recorded data, saved graph, and flushed titrator with deionized water.
  • Cleaned all glassware, set them to dry in their designated areas, and returned all equipment to its point of origin.
DRAFT: This module has unpublished changes.