Wednesday, 27 March 2013

Entry 14

HI!

So, for the first experiment, we had to investigate if changes of matter can be brought about by light if the substance of material is light sensitive. The experiment consisted of these few steps... 

Steps:

  1. Soak the filter paper with sodium chloride solution (NaCl)
  2. Place the filter paper on a clean white tile
  3. Drip 4 drops of silver nitrate solution all over the the filter paper. White precipitate will form on the filter paper. Ensure that the white precipitate covers the filter paper.
  4. Quickly place the opaque object on top of the filter paper, covering some of the white precipitate
  5. Place the paper in bright light for 15-20 minutes.
After the experiment was done and after awhile, we observed violet coloured stains on the filter paper.



For the next part of the experiment...



Thermal Decomposition
Steps:
  1. Add a level spatula of the copper (ll) nitrate solid into a test tube
  2. Gently heat the solid in the test tube over a bunsen flame
  3. Record any observations

The next experiment was really cool to cuz there was FIRE! 

Steps:
  1. In a beaker of soap water, bubble gas from the gas tap into the soap water
  2. Scoop a handful of bubbles
Light a lighter at the bubbles


Steps:
  1. Fill a boiling tube with potassium iodine solution and lead nitrilate solution
  2. Add 5 drops of lead nitrate solution to the boiling tube
  3. Record any observations
  4. Add water to the boiling tube until it is half full
  5. Heat the resulting mixture to obtain a near colourless solution 
  6. Allow the boiling tubes to cool on a test tube rack for approximately 10 minutes then place it in a beaker of water
  7. Record any observation
*steps 5-7 were conducted by the teacher

Precipitate formed when 2 colourless liquids are mixed together. 

Thank you for reading!! 
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