3.5 To determine the factors that affect the solubility of materials  (Page 2/3)

This is what a saturated solution looks like:

(Compare the sketch above to the previous sketch and ensure that you understand the difference.)

ASSIGNMENT 13 (GROUP WORK)

To prepare a saturated solution.

Requirements: Glass of tap water

White sugar

A teaspoon

• Fill the glass half full with tap water.
• Stir a teaspoonful of sugar into the water until it dissolves.
• Stir another teaspoonful of sugar into the water.
• Continue to add sugar to the water, until you observe that the sugar will no longer dissolve.

What do you observe?

1. How many teaspoons of sugar dissolved in the water?

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2. How are you able to dissolve more sugar in the water? Discuss this in your group.

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ASSIGNMENT 14

To investigate the formation of crystals.

• Make a saturated solution of copper sulphate and water.
• Place a small amount of the solution in a saucer and allow it to stand for a day.
• Write your observations and conclusions. You may use a microscope.

Observation:

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Conclusion:

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ASSIGNMENT 15

To determine how the type of substance affects solubility.

Requirements: Three clean glasses

Salt

Maize meal

Sulphur

Three teaspoons

Tap water

• Place exactly the same amount of water in each glass.
• Add one teaspoonful of salt to the first glass and stir carefully.
• Count how many teaspoons of salt can be added before the solution is saturated.
• Repeat the experiment using maize meal and sulphur instead of salt.

What do you observe?

1. Is the amount of soluble matter the same in each case?

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2. Which substance dissolved the least after the first teaspoonful?

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3. Is maize meal soluble?

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4. Which substance was most soluble?

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