Sunday 16 February 2014

2nd Science Laboratory Lesson ==>Making Observations

On 29 January, I had my 2nd Science laboratory lesson! The topic was on "Making Observations".

Therefore, we conducted a lot of mini-experiments and wrote down all our observations!

Well, the first experiment listed on the worksheet was not that interesting. It was to pour vinegar into a clean test tube to a depth of about 1cm, before adding a spatula of sodium bicarbonate. The observation was very intriguing though.  The water level of the vinegar rose before falling, and bubbles also appeared in the vinegar! Apparently, the explanation for this observation was that the sodium bicarbonate dissolves to form a colorless solution. Effervescence ( is the escape of gas from an aqueous solution and the foaming or fizzing that results from a release of the gas.) of a colorless and odorless gas was thus seen. 

For the second experiment, it was really interesting! We had to quarter fill two clean test tubes with water. Add a spatula full sodium carbonate to one test tube. Shake the test until the sodium carbonate dissolves. 
==> The observation was that the sodium carbonate dissolved to form a blue solution.


Add a dry spatula full of copper sulfate to the other test tube and shake it until the crystals dissolve.
==>A blue precipitate was seen and a colorless and odorless gas was given out. 

Now it comes to the interesting part: Pour the contents of the second test tube into the first test tube!
==> The bluish solution started to fizz!!!

Below is the results of the first test and second test!!!





For the third experiment, we had to place one drop of methylated spirits ( ethanol that has additives to make it poisonous, extremely bad tasting, foul smelling or nauseating, to discourage recreational consumption) onto the back of our hands. We then blew air gently across the back of our hands. It felt very cooling!

For the fourth experiment, I had to quarter fill a very small beaker with lime water. I had to gently blow through a drinking straw into the lime-water. 
==> White Precipitate was formed!

Before Blowing


After Blowing



For the 5th and last experiment, we were to place a few drops of starch suspension in a clean test tube and add a drop of iodine solution. 
==> The iodine solution turned blue-black!

The bottles of stuff we were supposed to use


The results





After that, we were tested on our observation skills! We were supposed to watch a YouTube video and write down as many observations of the burning candle that we could! WE were supposed to use all our candles except for sense of taste (which is obvious, unless we were supposed to lick the candle!! O.o).

Fun Fact: Michael Faraday(1791-1867), a scientist famous for his discoveries in electricity and chemistry, made 53 OBSERVATIONS of a burning candle!!! I only managed 14!


Do try out the activity and see how many observations you can write down!

This is the end of this post! I do hope that you have enjoyed it and I appreciate the time you spent on reading this post!!