🧪Paper Chromatography - Chemistry Experiment with Mr Pauller

Summary

This video script details a chromatography experiment aimed at separating the pigments in a wet erase marker ink. By drawing a line on chromatography paper and submerging it in water, the pigments' different properties cause them to travel at varying speeds, resulting in a colorful separation. The experiment concludes with measuring pigment distances and calculating the Rf values to quantify their solubility and movement relative to water.

Takeaways

• 🔍 The experiment demonstrates chromatography to separate pigments in a wet erase marker ink.
• 🖊️ Wet erase markers contain water-soluble pigments, which are the subject of the separation.
• 📝 The process starts by drawing a line on chromatography paper with the marker.
• 🌊 The paper is then placed in a beaker with water, allowing capillary action to draw the water up the paper.
• ⏱️ The video is sped up to 16x to show the quick separation of pigments into different colors.
• 🎨 The original black ink separates into various pigments due to their distinct properties.
• 🏃‍♂️ Different pigments travel at different speeds because of their varying solubility and weight.
• 📏 Post-experiment, the distances traveled by each pigment and the water are measured for analysis.
• 📐 The measurement starts from a common point to ensure a fair comparison of pigment travel distances.
• 🌈 The maximum distance traveled by the water and each pigment is recorded for further calculations.
• 🔢 The Rf (retention factor) value is calculated for each pigment, with 1 indicating the same travel as water and 0.5 half that distance.

Q & A

What is the purpose of the chromatography experiment shown in the video?

The purpose of the experiment is to separate the different pigments of ink present in a wet erase marker using chromatography paper and water.

Why are the pigments in a wet erase marker water-soluble?

The pigments are water-soluble because wet erase markers are designed to be easily removed with water, which allows the pigments to dissolve and separate during the experiment.

How does the water cause the ink to separate on the chromatography paper?

The water rises up the chromatography paper due to capillary action, carrying the ink pigments with it and causing them to separate based on their different properties.

What factors determine the speed at which the pigments travel up the paper?

The speed at which the pigments travel is determined by their differing properties such as weight, solubility in water, and density.

Why does the ink appear black before the experiment begins?

The ink appears black because the different pigments are mixed together and not separated, creating the appearance of a single black color.

What is the significance of measuring the distance traveled by each pigment?

Measuring the distance traveled helps in analyzing the results of the experiment, as it allows for the comparison of how far each pigment has moved relative to the water.

How should the distances be measured for a fair comparison?

For a fair comparison, all distances should be measured starting from the same point where the pigments began traveling, ensuring that the starting point for water and pigments is consistent.

What is the Rf (retention factor) value and how is it calculated?

The Rf value is a measure used in chromatography to indicate the distance a pigment has traveled relative to the solvent. It is calculated by dividing the distance traveled by the pigment by the distance traveled by the water.

What would be the Rf value for a pigment that travels the same distance as the water?

The Rf value for a pigment traveling the same distance as the water would be 1, indicating that it has moved with the solvent front.

What would the Rf value indicate about a pigment if it were 0.5?

An Rf value of 0.5 would indicate that the pigment has traveled only half the distance of the water, suggesting it is less soluble or more dense than the other pigments.