Experiment 1:
Separation of Metal Ions by Paper Chromatography
Purpose
The purpose of this experiment is to separate an unknown mixture of metallic ions by using the separation method of paper chromatography as well as to determine the identities of each ion in the mixture based on the position, colour, and retention factor of the spots created.
Procedure
1) Wearing gloves, use a pencil and ruler to draw a line 1.5cm from the bottom of the paper. On this line, mark 8 dashes 3cm from the sides and 2cm apart.
2) Make the developing solvent by pumping out 9mL of acetone and 1mL of 6M HCl into a graduated cylinder. In the fume hood, place a glass stir rod in the middle of a beaker and pour the solvent down the rod into the beaker. Tightly …show more content…
Cover with cling wrap.
4) Place a capillary tube into each test tube containing the metal ion solutions and apply one spot of each solution to its designated dash on the paper. Let the spot dry before repeating twice more. Use a different capillary tube for each solution to avoid cross-contamination.
5) Roll the paper into a cylinder and tape the two edges together, leaving a gap of about 0.5cm between the edges. Be sure that the edges are straight.
6) Carefully place the paper into the developing chamber. Recover the beaker and let the solvent rise up the paper until it is about 1.5cm from the top.
7) Once the solvent has travelled high enough, take it out of the chamber. Working quickly, unroll the paper, mark how far the solvent travelled, and circle all visible bands. Let dry.
8) Roll the dry paper back into a cylinder, carefully place it into the ammonia chamber, and recover. Let the chromatogram enhance for 5 minutes.
9) Take out the chromatogram and quickly circle all newly visible bands. Recover the …show more content…
Blue = = 0.61= Co+1
4. Pink = = 0.27 = Ni+2
By comparing the spots made by the known ions to the spots made by the ions in the unknown mixture, it can be confirmed that the unknown mixture contains Fe+3, Cu+2, Co+1, and Ni+2. Qualitatively, the colour of the spots all matched up throughout the whole experiment. The last step, applying the confirmatory reagent, confidently supports this result as all 4 unknown ions distinctly matched up to its respective known ion.
In addition to having the same colours, the spots also had very similar Rf values. To figure out how precise the results are, one can calculate and compare the differences in the Rf values. The differences in Rf values are as follows: Fe+2 = 0.04, Cu+2 = 0, Co+1 = -0.01, Ni+2 = 0.04. Cu+2 was exactly the same while the other three are almost exactly the same. A small difference indicates a high level of precision and though there are still possible errors, it assures that there was a lower chance of error occurring.
Possible Error
Possible Improvement
The sample spot was not completely dry before another spot was added on top. This could have caused the spot to spread and rise higher above the line, leading to the ion travelling higher and affecting the Rf
Separation of Metal Ions by Paper Chromatography
Purpose
The purpose of this experiment is to separate an unknown mixture of metallic ions by using the separation method of paper chromatography as well as to determine the identities of each ion in the mixture based on the position, colour, and retention factor of the spots created.
Procedure
1) Wearing gloves, use a pencil and ruler to draw a line 1.5cm from the bottom of the paper. On this line, mark 8 dashes 3cm from the sides and 2cm apart.
2) Make the developing solvent by pumping out 9mL of acetone and 1mL of 6M HCl into a graduated cylinder. In the fume hood, place a glass stir rod in the middle of a beaker and pour the solvent down the rod into the beaker. Tightly …show more content…
Cover with cling wrap.
4) Place a capillary tube into each test tube containing the metal ion solutions and apply one spot of each solution to its designated dash on the paper. Let the spot dry before repeating twice more. Use a different capillary tube for each solution to avoid cross-contamination.
5) Roll the paper into a cylinder and tape the two edges together, leaving a gap of about 0.5cm between the edges. Be sure that the edges are straight.
6) Carefully place the paper into the developing chamber. Recover the beaker and let the solvent rise up the paper until it is about 1.5cm from the top.
7) Once the solvent has travelled high enough, take it out of the chamber. Working quickly, unroll the paper, mark how far the solvent travelled, and circle all visible bands. Let dry.
8) Roll the dry paper back into a cylinder, carefully place it into the ammonia chamber, and recover. Let the chromatogram enhance for 5 minutes.
9) Take out the chromatogram and quickly circle all newly visible bands. Recover the …show more content…
Blue = = 0.61= Co+1
4. Pink = = 0.27 = Ni+2
By comparing the spots made by the known ions to the spots made by the ions in the unknown mixture, it can be confirmed that the unknown mixture contains Fe+3, Cu+2, Co+1, and Ni+2. Qualitatively, the colour of the spots all matched up throughout the whole experiment. The last step, applying the confirmatory reagent, confidently supports this result as all 4 unknown ions distinctly matched up to its respective known ion.
In addition to having the same colours, the spots also had very similar Rf values. To figure out how precise the results are, one can calculate and compare the differences in the Rf values. The differences in Rf values are as follows: Fe+2 = 0.04, Cu+2 = 0, Co+1 = -0.01, Ni+2 = 0.04. Cu+2 was exactly the same while the other three are almost exactly the same. A small difference indicates a high level of precision and though there are still possible errors, it assures that there was a lower chance of error occurring.
Possible Error
Possible Improvement
The sample spot was not completely dry before another spot was added on top. This could have caused the spot to spread and rise higher above the line, leading to the ion travelling higher and affecting the Rf