1. How Do Lava Lamps Work?

2. What is a Lava Lamp Really?
Lava lamps, for our purposes, are containers with a mixture of immiscible liquids
One liquid rises in blobs giving the appearance of lava
kinetics

3. What?
“Immiscible” - two things that don’t mix together (e.g., oil and water)
Surprising that the substances don’t mix because they are both liquids
Phases, intermolecular forces

4. What Does This Have to Do with Lava Lamps?
The lava lamp I will demonstrate is made of oil, water, and Alka- Seltzer
To understand why lava lamps are made of these ingredients let’s take a closer look at each one

5. Oil Oil molecules form an “induced dipole induced dipole interactions”
The interactions between the molecules aren’t that strong
Oil is hydrophobic

6. Water Water molecules interact through dipoles Water is hydrophilic
This makes water a
tetrahedral
Lewis dot diagram, vsepr

7. Alka-Seltzer Alka-Seltzer releases CO2 The CO2 makes the water float
reaction

8. This is like… Vinegar and baking soda experiment
H-Ac + NaHCO3 --> Na+ & Ac- & H2O & CO2 (gas)
Both reactions release CO2

9. Heat versus Alka-Seltzer
Alka-Seltzer replaces heat used in traditional lava lamps
Heat makes the molecules move faster
The faster they move, the size is increased, but the mass stays the same
Density is lowered, causing molecules to float

10. Put It Together The water sinks and the oil floats
When the CO2 attaches to the H2O it makes the water float
When the water reaches the top, the CO2 goes into the air and the water sinks back down

11. Which One Would You Choose?
Oil Molecule
Water Molecule

12. In Chemistry Terms Water can bond with oil but doesn’t want to
This is because the dipole dipole interaction of the water is stronger than the dipole induced dipole of the oil and water
This keeps the water moving because none of the water wants to be stuck next to the oil