Color of Gold Practical Report Essay

1165 Words Jun 21st, 2013 5 Pages
Nanotechnology | Colour of Gold | Practical Investigation Report | |

Introduction
Gold is a precious metal which has been used for years and when we think of gold we think of shining bars in a bank vault, coins or beautiful jewellery. When we think of gold it’s usually a shining yellow gold however can come in many colours. The colour of gold can range from red through the visible spectrum to purple and violet.

Aim
The whole point of this experiment was to create gold that wasn’t the colour gold. The aim was to find out how a variable amount of sodium citrate would change the colour of a gold solution. Meaning the hypothesis was: if more sodium citrate is added the nano particle size will increase and the colour of the gold
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* The magnetic stirrer can cause glass breakages if spun too fast.

Method
To create the colloid 1. Turn the hotplate on and heat to 300°C. 2. Using the pipette measure 20ml of the gold solution (HAuCl4) 3. Empty the gold solution into a 100ml conical flask. 4. Shine a laser through the solution to observe whether light is scattered. Scattered light won’t pass through in a straight line, and can’t be seen from the other side. 5. Shine the laser beam through the sodium citrate and observe scattering. 6. Place the flask containing the gold solution onto the hot plate. 7. Add the magnetic stirrer, and turn up to one third of possible speed. 8. Occasionally turning the spinner off to check, bring the gold to the boil. 9. Add a volume of 5% sodium citrate to the gold solution. 10. Keep the magnetic spinner stirring the mixture as the colour develops and changes. Turn the hotplate off so the mixture can simmer for about 10 minutes. Make sure the solution doesn’t boil. 11. When the colour change has finished remove the flask from the hotplate using the wooden peg to prevent burnt fingers and put onto a heat proof mat, and continue stirring with a stirring rod while the mixture cools.

Measuring the Colloid 1. 400μl
400μl
Dilute the colloid in a 2ml of the gold solution to 10ml of distilled water, and
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