SOLUBILITY
INVESTIGATION
If we stir salt crystals in water
they seem to disappear.
Where do the crystals go?
Some important terms
• A substance that dissolves: soluble
• A substance that doesn’t dissolve: insoluble
• How well something dissolves: solubility
• The solid that you are dissolving: solute
• The liquid that you are dissolving it in: solvent
• The product after dissolving: solution
• When no more solid will dissolve: saturated
OK, who remembered what?
solute
solvent
solution
Scientific Method
STEP 1: State the Question
Do most boys like ice cream?
Do 5G prefer the scenery on Mars or Jupiter?
How many boys in 5G prefer white chocolate to milk
chocolate?

detail?
doable? Oh Yeah!
Scientific Method
STEP 2: Formulate a Hypothesis (predicted result)
Most boys prefer milk chocolate.
I think 10 boys will prefer white chocolate.

detail?
40% of boys in 5G will prefer milk chocolate.
statement? 
Scientific Method
STEP 3: Identify Variables (things that vary)
What we are changing (Independent Variable):
Type of chocolate
What we are measuring (Dependent Variable):
Number of boys
What must stay the same for a fair test (Fixed variables):
Same time
Same amount of chocolate
Same temperature chocolate
Scientific Method
Variables for YOUR Investigation:
• Type of solute
• Type of solvent
• Temperature of solvent
• Speed of stirring
• Size of solute particles
• Apparatus used
• Time taken
Scientific Method
STEP 4: Method – detailed set of steps
1. Keep chocolate at room temperature for 1 hour.
2. Break slab of chocolate into pieces of 1 block each.
3. Give boys 1 piece of each type of chocolate to eat.
4. Count total number of boys.
5. Ask boys to raise hands if they prefer white chocolate.
6. Calculate percentage that prefer white chocolate.
Scientific Method
STEP 5: Results
1. Accurate.
2. Show all the details.
3. Remember to write down the units (grams, seconds, °C)
STEP 6: Analysis and Discussion
1. Bar Graph.
2. Is your hypothesis proved correct?
3. Do your results agree with background information?