IGCSE Coordinated Science Y1Topic: Methods of

Separation & Purification

Monday, August 27th Lesson 1

IN:

• Return to your lab station with your partner(s) and wrap up your separation lab.

• When you have obtained all 4 mixture components in plastic cups, clean up the rest of your lab materials and get checked off by Miss James.–Wash beakers, spoons, etc.

THROUGH:

C2 Vocabulary

• Before we talk about another method of separation, please get out your C2 vocabulary for Miss James to check off!

Chromatography

• Today’s method for separation is chromatography!

• Let’s go through the To “Dye” For Lab and discuss some background and technique information you’ll need to do your lab today!

To “Dye” For Lab

Separating Mixtures Using Chromatography

The Problem

• A lawsuit is pending between crayon and marker giant Crayola™ and the overhead pen/marker industry which includes Staedtler™, Monami, and Vis-a-Vis™. The various pen makers are claiming that Crayola™ has stolen their proprietary dye mixtures to use in their markers.

Your Challenge...

• You have been hired by the court as an independent consultant to use separation techniques that will analyze the components in the dye mixtures found in the pens and markers from each maker. Your findings should help clarify for the court whether or not a lawsuit is warranted.

The Science Behind Chromatography

• Chromatography means “Color Writing”• Chromatography uses the properties of

Solubility and Polarity to separate mixtures.

• There is a stationary phase (filter paper) and a mobile phase (water).

• Pigments that are more attracted to the mobile phase will travel farther across the medium than those attracted to the stationary phase.

Real Life Uses of Chromatography

• Observation of mixtures and solvents• To determine the identity of unknown

substances• To determine what is in a solid or liquid– Finding the presence of cocaine in urine– Detecting alcohol in blood– Finding toxins in fish– Detecting lead in water

• Chromatography is used in crime solving!

Procedure1. Fold your filter paper so that you have 4 equal

wedges (each wedge will contain a different color ink).

2. Fold your paper opposite the first folds so that the filter paper lays flat.

3. Using a PENCIL, trace a 500 won piece in the center of your filter—there will be NO marks here!

4. In one wedge, tap each marker of one color to the filter paper and label each dot near the outer edge of the filter paper. The smaller the dot the better!

5. Rest your paper on top of a large (250mL) beaker.6. Use a pipet to tap small drops of water to the

center of the filter paper.7. Observe!

OUT/Conclusion:

• Answer the following question:– Do Visa-Vis™, Monami, and Staedtler™

have a case against Crayola™? – Use observational “data” from your

experiment to support your conclusion. Appropriate data means detailed observations or drawings/sketches of your chromatograms.