EXPERIMENTAL INVESTIGATION 18.2 How does temperature affect the solubility of a substance?
Equipment Graduated cylinder
Water Beaker
Spatula
Glass stirring rod Mass balance
SAFETY • Wear gloves when handling the different substances.
• Be careful when handling the hotplate to avoid burns.
Hotplate Thermometer
Suggested substances to test Copper sulfate
Salt Sugar
• Allow equipment to cool before touching it.
• Do not ingest copper sulfate.
Method 1. Using a graduated cylinder, place 50 cm3
water in a beaker.
2. Slowly add the substance being tested to the water. Stir constantly. Add the substance using the spatula until no more of the substance will dissolve but instead settles to the bottom.
3. Measure the mass of the substance added to the water using a mass balance.
4. Using the hotplate and thermometer, heat the water to 40 °C and repeat step 2.
5. Repeat steps 2 and 3 at the following temperatures: 50 °C, 60 °C, 70 °C and 80 °C.
6. Follow steps 1–5 with a different substance.
100 120 140 160 180 200
20 40 60 80
0 20 40 50 60 Temperature (C) j Go to page 47 of your Experimental Investigations Log to write up this investigation. 70 80
(Fig. 18.9 A solubility curve showing sample results for sugar
:Fig. 18.8 To investigate the effect of temperature on solubility