Is all ice created equal?
Density lab
Name_____________
Purpose: To show that different molecules in a solid state melt in different ways
(sublimation), to practice density/mass/volume problems, and to obtain data and use that
data to come up with a conclusion.
Materials:
Gloves
Balance
solid ice cube (H2O) (should be relatively similar in size to dry ice pellets)
solid dry ice pellets (CO2)
2 25 ml beakers
1 piece of cellophane
1 rubber band
Safety:
Dry ice can cause severe cold burns and should therefore be handled carefully (gloves
should be used). Never ingest dry ice it can be fatal.
Procedures:
1) Do the pre-lab questions.
2) Obtain the materials listed above. Use gloves when toching the dry ice. Place the
dry ice in 1 beaker and the regular ice in the other. Put the piece of cellophane
over the dry ice beaker and rubber band it to the beaker.
3) Get an initial mass of each beaker (with the ice/dry ice in it) and an additional
mass every minute until the mass becomes constant (when all has
melted/sublimated). Record this mass in the table that you created.
4) Create 2 graphs (1 for each beaker) based off the information found in your table.
Pre-Lab Questions:
1) As the regular ice moves towards room temperature the ice will change from ice to
______________ in a liquid/solid/gas (circle one) state. As the dry ice moves towards
room temperature it will change from dry ice to _________________ in a liquid/solid/gas
(circle one) state.
2) Do you think the density of the dry ice will change as it gets warmer? How about the
regular ice?
3) Why does the regular ice and dry ice “melt” in different ways?
4) Create a table on the back of this sheet. On it include mass of each ice, volume, time
and density.
5) What is the volume in our experiment?
Post-Lab Questions
1) Did the mass of the ice change as the temperature got warmer? Did the mass of the
dry ice change as the temperature got warmer? Why or why not?
2) Did the density change? Why or why not?
3) How does the graph help us interpret our results?
4) What are some possible errors that could have skewed data?
Table (you need to create this)
Don’t forget your 2 graphs!!!