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Making gold crystals
Equipment needed:
- 3 Clean test tubes and rack
- Stirring rod
- 250cm3 beaker
- Bunsen burner, tripod and gauze
Chemicals needed:
- Potassium iodide solution
- Lead nitrate solution
Instructions:
- Collect 10 cm3 of potassium iodide solution
in a clean test tube.
- Collect 10 cm3 of lead nitrate solution
in a second clean test tube.
- Heat 100 cm3 of water in a 250 cm3
beaker until it boils gently.
- Mix the two solutions together in a third clean test tube and add
the contents a little at a time into the hot water stirring throughout
- Allow to cool and observe.
Observations
Before, during and after – colour, state and any other observations.
Don’t forget that it is often better to present data in the form of a
table.
For example:
| Appearance |
Before |
During |
After |
| State |
|
|
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| Colour |
|
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| Other observations |
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Write up:
| Aim: |
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What do you hope to find out |
| Hypothesis: |
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Not needed in this case |
| Method: |
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Refer to the instructions and include any changes you
had to make |
| Diagram: |
|
Show any assembled apparatus or complexoperations carried
out. |
| Results: |
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Tabulated if possible |
| Conclusions: |
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How can you explain your results |
| Evaluation: |
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Do you think that the experiment is adequate for the
aim? Can it be improved? What would you do if you were to do it again? |
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