Chromatography: Mixture and Coffee Filter
Chromatography: Separating Mixtures
Introduction:
Magic marker inks are often mixtures of several compounds. Paper chromatography is a common method of separating various components of a mixture. After separation, you can observe the different colors that make up a particular color of magic marker ink.
You can also calculate a ratio Rf, which compares how far each compound traveled to how far each solvent (substance that dissolves another substance) traveled during the experiment.
Rf = Ds/Df
Ds = Distance traveled by the compound
Df = Distance traveled by the solvent
Materials:
coffee filter, tape, rubbing alcohol, water, 3 different color magic markers (not permanent); 3 identical tall, narrow drinking glasses; metric ruler, 3 pencils
Pre-lab Questions: 1. List one extensive and one intensive property of marker ink.
Extensive – volume, Intensive – color
2. Define mixture.
Mixture – a substance made by combining other elements together. - the process of mixing or being mixed
3. Is tap water a heterogeneous or homogenous mixture? Explain your answer.
I think that it is heterogeneous because it’s not pure water.
4. Is rubbing alcohol a heterogeneous or homogenous mixture? Explain your answer.
It’s a homogeneous mixture because it is a pure substance.
Procedure:
1. Cut 3 strips of coffee filter. Be sure that the strips are much narrower and slightly taller than the drinking glasses.
2. In the center the strips, about 3 cm from one end, place a dot of the marker to be tested. The dots should be about 0.2 cm in diameter and dark enough to be clearly visible.
3. Place about 2 cm of water in each glass.
4. Tape the unmarked end of each strip to the center of a pencil so that the strip hangs down when the pencil is held horizontally.
5. Carefully insert the strips into the glasses, dotted end down. The dot must be above the water, and the sides of the coffee filters cannot
Introduction:
Magic marker inks are often mixtures of several compounds. Paper chromatography is a common method of separating various components of a mixture. After separation, you can observe the different colors that make up a particular color of magic marker ink.
You can also calculate a ratio Rf, which compares how far each compound traveled to how far each solvent (substance that dissolves another substance) traveled during the experiment.
Rf = Ds/Df
Ds = Distance traveled by the compound
Df = Distance traveled by the solvent
Materials:
coffee filter, tape, rubbing alcohol, water, 3 different color magic markers (not permanent); 3 identical tall, narrow drinking glasses; metric ruler, 3 pencils
Pre-lab Questions: 1. List one extensive and one intensive property of marker ink.
Extensive – volume, Intensive – color
2. Define mixture.
Mixture – a substance made by combining other elements together. - the process of mixing or being mixed
3. Is tap water a heterogeneous or homogenous mixture? Explain your answer.
I think that it is heterogeneous because it’s not pure water.
4. Is rubbing alcohol a heterogeneous or homogenous mixture? Explain your answer.
It’s a homogeneous mixture because it is a pure substance.
Procedure:
1. Cut 3 strips of coffee filter. Be sure that the strips are much narrower and slightly taller than the drinking glasses.
2. In the center the strips, about 3 cm from one end, place a dot of the marker to be tested. The dots should be about 0.2 cm in diameter and dark enough to be clearly visible.
3. Place about 2 cm of water in each glass.
4. Tape the unmarked end of each strip to the center of a pencil so that the strip hangs down when the pencil is held horizontally.
5. Carefully insert the strips into the glasses, dotted end down. The dot must be above the water, and the sides of the coffee filters cannot