Chemlab: Chemistry 3/5


Natural Salt Solutions 2: Analysis of Seawater

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Titration graphic
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Titration
Quantitative Transfer
Goals
This week you will use an ion exchange column to analyze a sample of natural seawater. Cations in the sample will be exchanged on a column for H+ ions. The acidic effluent solution will then be analyzed by titration with base. You will also determine the concentration of the base solution by standardizing it with a standard acid, potassium hydrogen phthalate (KHP).

Key Questions
1. How can I be sure that I convert every cation in the sea water sample to a hydrogen ion and then collect every H3O+ for analysis?

2. What must I do to maintain the concentration of the NaOH solution used for titration?

3. How can I make my titrations reproducible, so I can believe the value I obtain?

4. How can I evaluate the uncertainty of my results?
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