Name:
Period:
Chemical Vs. Physical Changes Lab
Objective:
Students will investigate physical vs. chemical properties, and physical vs. chemical
changes. Students will apply these concepts to making ice cream.
Background Information:
In order for matter to change phases (a physical change), heat must be either gained or
lost. Phase changes occur all around us in everyday life. For example, ice melts when a drink is left
in a room at normal room temperature; water freezes when placed in a very cold temperature
(like a freezer). In this experiment, we will see how heat is lost in order to change the milk from a
liquid into a solid state. This is an example of a physical change in matter. Students will also
observe how adding a solute (salt) to a solvent (ice) can change the physical properties of that
solvent. In this case, the freezing point of the ice is lowered, allowing the milk to turn into ice
cream.
Materials (per pair of students):
 250 mL milk
 50 mL sugar
 2.5 mL vanilla extract
 1 gallon size freezer bag
 1 quart size freezer bag





ice
salt
paper towels
2 Dixie cups
2 spoons
Procedure:
1. Carefully pour the milk, sugar, and vanilla extract into your quart size bag. Make sure the bag is
COMPLETELY sealed – squeeze out as much air as possible – and thoroughly shake the mixture.
2. Put the quart bag inside the gallon bag. Add enough ice to cover the smaller bag, then pour salt
over the ice.
3. Squeeze out as much air as possible, then seal the gallon bag. Make sure it is COMPLETELY
sealed!
4. Take turns flipping and turning the bag – remember to hold the bag over the table at all times!
Your mixture should take about 10-15 minutes to freeze all the way through.
5. When your mixture is frozen, take the quart bag out of the gallon bag and dry it off. Dump the
ice/salt combination into the sink – DO NOT THROW YOUR GALLON BAG IN THE TRASH! Lay it
beside the sink after it has been emptied.
6. Split your ice cream between the two Dixie cups and enjoy!
Name:
Period:
Chemical Vs. Physical Changes Lab
Objective:
Students will investigate physical vs. chemical properties, and physical vs. chemical
changes. Students will apply these concepts to making ice cream.
Background Information:
In order for matter to change phases (a physical change), heat must be either gained or
lost. Phase changes occur all around us in everyday life. For example, ice melts when a drink is left
in a room at normal room temperature; water freezes when placed in a very cold temperature
(like a freezer). In this experiment, we will see how heat is lost in order to change the milk from a
liquid into a solid state. This is an example of a physical change in matter. Students will also
observe how adding a solute (salt) to a solvent (ice) can change the physical properties of that
solvent. In this case, the freezing point of the ice is lowered, allowing the milk to turn into ice
cream.
Materials (per pair of students):
 250 mL milk
 50 mL sugar
 2.5 mL vanilla extract
 1 gallon size freezer bag
 1 quart size freezer bag





ice
salt
paper towels
2 Dixie cups
2 spoons
Procedure:
1. Carefully pour the milk, sugar, and vanilla extract into your quart size bag. Make sure the bag is
COMPLETELY sealed – squeeze out as much air as possible – and thoroughly shake the mixture.
2. Put the quart bag inside the gallon bag. Add enough ice to cover the smaller bag, then pour salt
over the ice.
3. Squeeze out as much air as possible, then seal the gallon bag. Make sure it is COMPLETELY
sealed!
4. Take turns flipping and turning the bag – remember to hold the bag over the table at all times!
Your mixture should take about 10-15 minutes to freeze all the way through.
5. When your mixture is frozen, take the quart bag out of the gallon bag and dry it off. Dump the
ice/salt combination into the sink – DO NOT THROW YOUR GALLON BAG IN THE TRASH! Lay it
beside the sink after it has been emptied.
6. Split your ice cream between the two Dixie cups and enjoy!
Name:
Period:
Chemical Vs. Physical Changes Lab
Questions:
1. What phase of matter was the milk in when you began?
2. What phase of matter what the milk in when you finished?
3. Was this a physical or chemical change? How do you know?
4. What had to be removed in order to change the phase of the milk?
5. Why did you add salt to the ice?
6. If you had not added sugar to the milk, would it have frozen faster? Why?
(take your best guess and EXPLAIN your answer!)
7. Why do you think the outside of the gallon bag got wet? (assuming there were no leaks)
BONUS: What type of mixture is the ice cream (homogeneous/heterogeneous)? How could you
make it a different type of mixture?
Name:
Period:
Chemical Vs. Physical Changes Lab
Questions:
1. What phase of matter was the milk in when you began?
2. What phase of matter what the milk in when you finished?
3. Was this a physical or chemical change? How do you know?
4. What had to be removed in order to change the phase of the milk?
5. Why did you add salt to the ice?
6. If you had not added sugar to the milk, would it have frozen faster? Why?
(take your best guess and EXPLAIN your answer!)
7. Why do you think the outside of the gallon bag got wet? (assuming there were no leaks)
BONUS: What type of mixture is the ice cream (homogeneous/heterogeneous)? How could you
make it a different type of mixture?