II. Date: October 3rd, 2012
III. Purpose: To separate a mixture using paper chromatography.
1. Fill beaker with 100 mL water.
2. Poke hole in filter paper with scoopula approximately 1 cm from top. 3. Place dot of ink approximately 2 cm from the bottom of the filter paper. 4. Put scoopula through hole and hang paper from scoopula so that it touches the water, making sure Ink dot is not submerged. 5. Repeat steps 1-5 using second color of ink.
6. Observe for 15 minutes, or until water reaches scoopula.
V. Observations and Data:
The filter paper was placed above the water with a colored dot 2cm from the bottom of the paper. Then while sitting over the water the color ran up the filter paper.
Using paper chromatography, we were able to see the mixtures of the marker separate.
VII. Questions for Discussion:
1. How did the filter paper change during this procedure? The paper went from dry to the entire thing being wet, without the whole paper in the water. 2. What evidence is there that ink is a mixture?
The evidence that is shown is the different colors that ran up the paper. It went from one color to the next. 3. A forensic scientist is someone who examines evidence gathered at a crime scene. What type of evidence could a forensic scientist examine using chromatography? Explain why chromatography would be useful. Using chromatography, scientists can see if other substances are mixed with the blood. It would be useful to see why an illness has occurred or other medical problems. Chromatography is separation technique. One way a blend of colors in a mixture can be separated is by using chromatography. Chromatography literally means color writing. The colors in a mixture can be separated by a combination of absorption and capillary action. The filter paper holds the substances that make up the different colors by absorption and the capillary action of a liquid pulls the different colored substances up the paper at different rates. Pigments or colors are separated on the paper and show up as different streaks.
250 mL beaker
Marking pens containing black ink and brown ink