Investigate Chromatography Worksheet - EdPlace - Free Printable

The image you've provided is a simplified representation of chromatography, a technique used to separate mixtures into their individual components based on differences in how they interact with a stationary phase and a mobile phase.

Let’s analyze the diagram:

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🔬 Understanding the Diagram

- The horizontal line at the bottom represents the starting point (origin) where the sample was applied.
- The vertical axis (implied by the positions of the spots) shows how far each component has traveled during chromatography — this is called the migration distance.
- The colored spots represent different pigments or compounds that have separated from the original mixture.
- Each spot's position corresponds to its Rf value (retention factor), which is calculated as:

\[
R_f = \frac{\text{Distance traveled by the compound}}{\text{Distance traveled by the solvent front}}
\]

However, in this diagram, the solvent front isn't shown, so we can only compare relative distances.

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🎨 Observations

There are four starting points labeled:
1. Purple
2. Green
3. Yellow
4. Brown

From each starting point, multiple colored spots appear above it. These likely represent the components of each pigment when separated via chromatography.

Let’s examine what happens for each:

#### 1. Purple
- Two spots:
- Blue (lower)
- Red (higher)

👉 This suggests that purple is a mixture of blue and red pigments.

#### 2. Green
- One spot:
- Green

👉 Green appears to be a single component or a pure pigment that does not separate further under these conditions.

#### 3. Yellow
- One spot:
- Yellow

👉 Yellow also appears as a single component.

#### 4. Brown
- Two spots:
- Blue (lower)
- Red (higher)

👉 Brown separates into blue and red, similar to purple.

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🧪 Interpretation

This diagram illustrates that:

- Purple and brown are mixtures of red and blue pigments.
- Green and yellow are pure pigments or do not separate under these conditions.
- The height of the spots indicates how much the pigment moved — possibly due to solubility or affinity to the stationary phase.

> In real chromatography, the Rf values would help identify substances. Here, since no scale is given, we infer based on relative positions.

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✔ Conclusion

The chromatography result shows:

| Original Color | Separated Components |
|----------------|------------------------|
| Purple | Blue + Red |
| Green | Green (no separation) |
| Yellow | Yellow (no separation) |
| Brown | Blue + Red |

So, purple and brown are mixtures, while green and yellow are pure in this context.

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💡 Educational Insight

This kind of experiment is common in biology or chemistry labs to study plant pigments (like chlorophylls, carotenoids). For example:
- Chlorophyll might show green,
- Carotenoids might show yellow/orange,
- And some dyes may break down into primary colors.

In this case, the visual representation teaches us that colors we see aren’t always pure — they can be combinations of simpler ones.

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If you have a specific question about this (e.g., "Which color contains both red and blue?", or "What does the height mean?"), feel free to ask!