Experimental procedure (ions)
Start by gathering the materials required for the experiment. Record your findings in a table.
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Use a pencil to mark a line 3 cm from the end of the Whatman filter paper. This is the reference line.
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Using a finely drawn capillary, put one spot of the lead cadmium solution on the reference line. Label the spot under the reference line and make a note of the label in your lab book.
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Hang the filter paper in a jar containing 20 mL of a mixture of ethanol, 6 M HNO3, and distilled water, in the ratio 8:1:1. The paper should hang so the solvent does not touch the reference line.
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Keep the jar as still as possible until the mobile phase has gone up two thirds the length of the paper.
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Remove the filter paper from the jar. Use a pencil to mark the solvent front.
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The developer ammonium sulfide is prepared by passing H2S gas through a mixture containing 100 mL of water and 10 mL of liquor ammonia for about 45 minutes.
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Spray the ammonium sulfide solution on the chromatography paper to obtain yellow and black spots. Markt the positions of the spots with a pencil, and allow the paper to dry.
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Measure the distance traveled by the solvent front and the center of the spots with respect to the reference line.
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Calculate the Rf value of the different spots. Use the equation found here.
References:
- NCERT Chromatography handbook