Types of Solutions Lab
Name: _______________________________________
Date: _________
Problem: How can you tell the difference between an unsaturated, saturated, and
supersaturated solution?
Materials: 10ml graduated cylinder, test tube, spoon, hot plate, 250 ml beaker, water, sodium
acetate (NaAc)
Procedure:
1. Use a graduated cylinder to add 2.5 ml of water to your test tube, then add
approximately 3 crystals of sodium acetate (NaAc) and swirl until the NaAc is dissolved.
2. Add approximately 3 more crystals and swirl.
a. Did they dissolve? __________
b. If so, was the solution saturated at first? ________________
c. Can you tell if it is saturated now? ______________________
3. Add 1 level spoonful of NaAc and swirl for at least 1 minute.
a. Did the temperature change? If so, how? ________________________
4. Add approximately 1 crystal and swirl 1 minute.
a. Did this crystal dissolve? _________________
b. Can you tell if it is saturated now? __________________________
5. Add 4 more level spoonfuls of crystals and heat the test tube in a water bath until the
crystals dissolve. Swirl periodically while heating to dissolve all crystals.
6. Put approximately 200ml of very cold water in to a 250 ml beaker and place the test
tube in the water. Let stand for 5 minutes. DO NOT DISTURB while standing! If crystals
form in this time, reheat to dissolve, and then cool again.
7. Take the test tube out of the water and add 1 crystal of NaAc.
a. What happened? ______________________________________________
b. Did the temperature change? If so, how? ____________________________
8. Rinse out the test tube (heat if necessary) and return all materials to where you got
them.
Types of Solutions Lab
Name: _______________________________________
Date: _________
Conclusion Questions:
1. What experiment could you do after step 5 to determine whether or not the solution
was saturated?
2. After completing step 7, how would you describe the saturation of the solution?
3. Explain the observed temperature changes as the NaAc dissolved and then crystallized.
a. Did the temperature change of the NaAc dissolving in step 3 indicate that energy
was going in to or out of the water? ____________________________
b. Does this mean that the NaAc gained or lost energy when it was dissolving? Describe
the change in movement of the NaAc particles to support your answer.
c. Did the temperature change of the NaAc crystallizing in step 7 indicate that energy
was going in to or out of the water? ________________________
d. Does this mean that the NaAc gained or lost energy when it was crystallizing?
Describe the change in movement of the NaAc particles to support your answer.