#13 Entry- Kinetic Particles Theory (Chemical Changes) Practical 1

Haven't been posting for a long time!

Today, we did two main practicals, than consisted of many small procedures that were both easy and fun to do.

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.

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.

Violet-Coloured Filter Paper

For the next part, Mr Foo demonstrated as heating was required.

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

thermal decompostion

Next experiment that the teacher did was cool because it involves lighting a fire in water!

Steps:

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

Didn't manage to get a picture though.

Explanation: Particles move faster, hence there is more spaces between the particles. The substance will then be able to fill up the spaces between the molecules. Hence The water and the fire are actually separated. Thus the water cannot extinguish the fire.

After that, we conducted an experiment by ourselves

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

when 2 colourless liquids were mixed together, they formed a bright yellow substance

While being heated, the yellow substance dissolves and forms a solution (clear)

lastly, the acids and whatnot

the end!