Observation Vs Inference

Note: This Lesson was completed on the 29th January.

At the lab, we tested our observations with a series of experiment. The Experiments are as follows:

Firstly, To add Sodium Bicarbonate to Vinegar, or chemically, add NaHCO3 to C2H4O2. 
Next, add Sodium Carbonate and Copper Sulfate respectively to Water.
Thirdly, Use a dropper to place one drop of Methylated Spirits onto the back of our hand and blow air gently across.
Fourth, Blow Carbon Dioxide to Limewater.
Fifth, Add Iodine to Starch.

The observations was as follows:
For the First, the Sodium bicarbonate dissolved to form a colourless solution. Effervesence of a colour less and odourless gas was seen.
Two: The Sodium Carbonate dissolved to form a clolourless solution. So the the Copper Sulfate, but instead blue precipitate was formed.
Three: There was a cooling sensation.
Four: White Percipitate was formed.
Fifth: It turned Blue Black.

Below are some photos in the experiment.

Empty test Tube

The Four Substances Required for Experiment 1 & 2

Copper sulfate and Water Mixture

The Three Test Tube Mixtures of:
Sodium Bicarbonate + Vinegar
Sodium Carbonate + Water
Copper Sulfate + Water

Lime Water

Blowing into the lime water

The result of  Limewater and Carbon dioxide

Starch and Iodine

Iodine, Starch, and the Mixture in Between

Another observation test we did was with this video.
See how many observations can you  make!



On average, we did 15 to 19 observations, though the highest was 25 to 30, the mode was 20 to 24, and 2 people completed the lowest range of 5 to 9. Personally, I did 18, and I was really surprised that some guy could do 25 to 30 observations.