05.05 Mixtures and Solutions
Background: Paper chromatography is one method for testing the purity of compounds and identifying substances. Paper chromatography is a useful technique because it is relatively quick and requires small quantities of material.
Safety: Warnings: * Rubbing alcohol (or isopropyl alcohol) is flammable, so be sure to keep it away from high heat or heat sources. * Keep pigments and solutions away from your eyes, wash your hands carefully after coming in contact with any solutions or pigments, and clean up spills with soap and water immediately after they occur. * This lab can be a little messy, so be sure to work at a kitchen counter or in another area that can be easily wiped down if anything spills.…show more content…
5. Prepare the salt solution by mixing 1/8 teaspoon of salt and three cups of water in a clean pitcher or 2-liter bottle. Stir or shake the solution until it is dissolved. This will produce a 1% salt solution. 6. Pour the salt solution into a clean tall glass so that the liquid level is 1/4 inch (0.5 cm). 7. Tape the strip to a pencil and rest the pencil on top of the jar so that the strip hangs into the jar. The goal is to have the end of the chromatography strip just touching the surface of the solvent solution, with the colored dots above the surface of the liquid. Make sure that the colored spots do not come in direct contact with the liquid in the bottom of the glass.
1. Capillary action will draw the salt solution up the paper. As it passes through the dots, it will begin to separate the dyes. When the salt water is 1/4 inch (0.5 cm) from the top edge of the paper, remove it from the glass and place it on a clean, flat surface to dry. 2. Repeat steps two through nine (using the second strip of paper and a clean glass) to test the same four colors using the alcohol instead of the saltwater solution at the bottom of the glass.
Salt Water | Isopropyl alcohol | Went very far | went not very far |
The salt water went further than the Isopropyl. When I placed the paper with the ink in the salt water, it went up to the end of the paper. However with the