Natural Salt Solutions 2: Analysis of Seawater Overview Getting Started Techniques Procedure FAQ Full Lab Manual Introduction & Goals Chemistry & Background Key Questions Prelab Problems Safety Procedure In Your Write-up Appendix Experiments Index ChemLab Home		Standardization of NaOH solution with KHP Pick up the samples of KHP that you weighed and stored last week. Transfer the solid from one vial to a clean Erlenmeyer flask. Be sure that you make a quantititive transfer. Add water and swirl to completely dissolve the solid. Your sample is ready to titrate. Prelab Problem 2 A KHP sample weighing 0.1960 g is titrated with 0.1246 M NaOH. How many milliliters NaOH would you expect to add to reach the endpoint? The molecular formula of potassium hydrogen pthalate (KHP) is C8H5O4K. You can easily calculate the molecular mass using the molecular mass calculator in the periodic table, elsewhere on the site. Charging a Column with Seawater and Testing the Effluent Add sea water to the top of the column slowly and carefully, so as not to disturb the resin bed. You can pour solution slowly down the side of the column opening or add solution dropwise, with a pipet. Make sure the seawater is transferred quantitatively to the column. Rinse the column with two aliquots of distilled water, collecting all the eluted solution. After rinsing, test the pH with indicator paper by taking a drop of effluent to piece of paper on a watch glass. How will you tell when you have completely exchanged the seawater cations and collected all the H+ that results? Titration of effluent To titrate the effluent of your sea water ion exchange analysis, use the same procedure you used to standardize the NaOH solution. For details see the titration link, below. Technique Links quantititive transfer buret titration pipet
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