Research question
How does temperature affect the dissolving time of various salts.?
Hypothesis
I predict that with water of high temperature the salts will dissolve quicker.
Controlled Variable
Amount of water (solvent)
Amount of salt used (solute)
Type of cups taken and their sizes
Independent variable
Temperature of water
Dependent variable
Time taken for each salt to dissolve
Material Required
Measuring Cylinder
Thermometer
Weighing Balance
Glass rod
Cups
Water
Salt e.g. Alum
Procedure
1. Heat a couple of litres of water to 60oC and take 150 mL using a measuring cylinder.
2. Pour the water into a cup along with the 10g of the salt taken e.g. NaCl and start timing immediately when it is placed in. Stir with the glass rod to help it dissolve.
3. When the substance is no longer visible it is done dissolving. Immediately stop- the timer and record the time taken.
4. Do this five times using different cups for each trial.
5. Repeat steps 1-4 taking water of temperature 80oC and then 100oC.
6. Calculate the average dissolving time for each and record.
Results
|Temperature of water|Trial 1 (seconds) |Trial 2 (seconds) |Trial 3 (seconds) |Trial 4 (seconds) |Trial 5 (seconds) |Average Time |
|oC | | | | | |(seconds) |
|60 | | | | | | |
|80 | | | | | | |
|100 | | | | | | |
Controlling the controlled variables