## Monday, 29 December 2014

### 1.2.1 Laboratory Activity : Scientific Investigation method

 Laboratory Activity 1.2.1: Scientific Investigation method
Aim: Investigating the effect of the temperature of water on the solubility of sugar
Problem statement: Does the amount of sugar that dissolve in water increase when the temperature of water increase?
Hypothesis: The higher the temperature of the water, the greater the mass of sugar that dissolve in it.
Variable:
 » Fixed variable : Volume of water and size of sugar » Manipulated variable : Temperature of water » Responding variable: Amount of sugar that dissolves at different temperatures
 Material: » Sugar » Water Apparatus: » 100 ml measuring cylinder » 250 ml beaker » Electronic balance » Bunsen burner » Tripod stand » Wire gauze » Spatula » Thermometer » Glass rod
Procedures:

The animation below shows the arrangement and the results of the experiment.

 1. 100 cm³ of water is measured using a measuring cylinder and is poured into a 250 cm³ beaker. 2. The temperature of the water is recorded using a thermometer. 3. 100 ml beaker is filled with sugar. The beaker and its contents are then weighed and recorded as a gram. 4. The water is added a little at a time to the 100 cm³ of water in the beaker using a spatula. The mixture is then stirred using a glass rod. 5. The process is continued until no sugar can further dissolve in the water. 6. The beaker and its sugar content is weighed again and recorded as b gram. 7. The amount of sugar that dissolved in the water at room temperature is (a - b) gram. 8. The experiment is repeated by heating the water to temperatures of 40 ºC, 50 ºC, 60 ºC and 70 ºC respectively.
Results:

 Temperature (ºC) Room temperature 40 50 60 70 Initial mass of beaker and its contents(g) a b c d e Final mass of beaker and its contents(g) b c d e f Mass of sugar dissolve(g) a-b b-c c-d d-e d-f

A graph of the mass of sugar dissolved against temperature is plotted.
Conclusion: The amount of sugar that dissolves in the water increases when the temperature of the water increases. The hypothesis is accepted.