User:Douglas M. Fox/Notebook/AU CHEM-571 F2011 Lab Support/2012/01/25

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Project 3: Solution Preparations Main project page
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Project Objectives

Standardization of NaOH (titrant) & HCl stock solutions
Preparation of 2.7 mM chlorauric acid solution
Preparation of buffer solutions

Today's Tasks

Standardization of NaOH titrant solution (trial 1)

  • Using "0.2 M NaOH" stock solution as a titrant
  • Using Orion 5-Star meter with pH electrode
  • Meter calibrated with homemade 1:1 HAc/NaAc and 1:1 Borate buffers
  • Potassium Hydrogen Phthalate (KHPth) is a primary standard for acid/base solutions

Analyzed Data

Dried 10 g KHPth overnight at 110 °C
Placed 1.04 g KHPth in 250 mL Erlenmeyer flask & added 50 mL water (grad cyl)
After dissolution, added 3 drops phenolphthalein
Added base in 0.2 - 5 mL increments, measuring pH at each step
Data file available in DropBox