4 Classes of Reactions Used quantitatively

1
4 Classes of ReactionsUsed quantitatively
Precipitation Gravimetric Ca calcium
oxalate Acid/Base Volumetric Acid KHP OH
Redox Gasiometric Nitrite NO2- H
NH2SO3 ? N2 HSO4 H2O Complexation
This lab Volumetric
Ca Zn EDTA
2
Volumetric Determination of Zinc and
Calcium Using Complexometric Titration First
Week 1) Preparation and Standardization of
EDTA solution (10ppt) 2) Use
SciFinder Scholar or Web of Science to find
reference (page 3) Second
Week 1) Analyze Water Sample for Ca2
You must do this first!!! 2)
Analyze Cold-Eeze Lozenge for Zn2 3) Check-in
Course Evaluations
3
Development of Cold-Eeze Lozenges
One of the people involved in the designed to
reduce the duration and severity of the common
cold by introducing zinc ions into the body is
J. C. Godfrey
We are going to get one of the references in his
research that talks about this research to
treat the common cold, using Scifinder Scholar
or Web of Science. The Libraries of The
Claremont Colleges
You will do this in the computer room (113) after
completing standardization.
Write down the reference and a one sentence
summary of the abstract in your report.
4
Polydentate or Multidentate Ligands
Like NH3
1 Ligand, but 2 bonds
Like CO32-
Called Chelates (claw)
5
2
1
5
6
3
4
Fully deprotonated EDTA can bind to metal ion at
6 sites
6
(No Transcript)
7
Indicator InMetal complex is one color Add EDTA
? EDTAMetal At endpoint InH a different
color Make mock solution for comparison
Note that there are 2 different indicators- one
for Ca and one for Zn
8
Week 1 Standardize CaCO3

• Prepare 500 ml of a 0.020 M EDTA solution
• Use 250 ml volumetric flask to the mark emptying
  into a clean 800 mL beaker, repeat. Dissolves
  slowly (gt 5 min). Heat if necessary but cool
  before titrating.
• Preparation of the CaCO3 in volumetric flask
• Also, after titrating, use SciFinder Scholar or
  Web of Science in 113.

9
Week 2 Water and Lozenge Analysis

• Make buffer solution
• Titrate water samples
• Water hardness results go to Prof.Reinen of
  Geology
• Titrate three lozenges
• Make sure to take masses of each before crushing
  with mortar pestal and determine amount used in
  each titration