8.7: Laboratory Questions

1. Was the initial mass of graduated cylinder the same before you added the oil and before you added the water? Why or why not?
2. Which liquid had a higher density, water or oil?
3. Which liquid floated on top of the other? What conclusions can you draw about the relationship between the density of a substance and how it interacts with another substance?
4. Did the food coloring sink or float in the oil? How does the density of the food coloring compare to the oil?
5. Did the food coloring sink or float in the water? How does the density of the food coloring compare to the water?
6. Do the food coloring and the oil have similar intermolecular forces? What data did you use from your experiment to reach your conclusion?
7. Do the food coloring and the water have similar intermolecular forces? What data did you use from your experiment to reach your conclusion?
8. Water is H-O-H and bent in shape. This molecule is polar. What intermolecular forces are present in water?
9. Oil is made of molecules that have only C-H and C-C bonds. Is this molecule polar or nonpolar? Why?
10. What type of intermolecular forces are present in oil?
11. Consider the following statement:

• Nonpolar molecules with only dispersion forces are still attracted to polar molecules with dipole-dipole or H-bonding intermolecular forces. However, the polar molecules are more attracted to each other and thus exclude the nonpolar molecules.

Does your experimental data support this statement? Why or why not? Think about what happened when you mixed the oil and water.

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