chromatography Flashcards
What is chromatography used for?
To separate materials in a mixture
What are the two phases in chromatography?
- Mobile phase
- Stationary phase
How do components in a mixture separate during chromatography?
Depending on their affinity for the stationary or mobile phase
What is the stationary phase used in the described chromatography experiment?
Paper
Why is pencil used to draw the baseline in chromatography?
pencil doesnt move in the mobile phase
What is the mobile phase introduced in the chromatography experiment?
Water
True or False: The water level in the beaker should be deeper than the dots on the paper.
False
What is used to suspend the chromatography paper in the beaker?
A glass rod
What does the Rf value represent in chromatography?
Retention factor
How do you calculate the Rf value?
Rf = (Distance traveled by the color) / (Distance traveled by the solvent)
What must be done between applications of different colors on the chromatography paper?
Allow the color to dry
Why is it important to use a different capillary tube for each color?
To avoid cross-contamination
What happens to the colors in the food dye during chromatography?
They either dissolve in the water or stay on the paper
True or False: The chromatogram shows that the red food coloring was present in the unknown sample.
False
What is the first measurement needed to calculate the Rf value?
Distance the solvent has traveled
What does the term ‘capillary action’ refer to in chromatography?
The ability of the liquid to flow in narrow spaces without external forces
What should be done after the chromatography process is complete?
Let the paper dry
What is the significance of the pencil line drawn at the top of the paper?
It indicates the distance the solvent traveled
