Physics Lab: Investigating Water In Water

Procedure:

Obtain an empty aluminum can, ice bath, metal tongs and a hot plate

Turn on the hot plate to maximum temperature

Add a very small amount of water to the empty can and place it upright on the hot plate

Wait until you see steam rapidly escaping the can and then use the tongs to quickly turn it upside down in the ice bath

Observations:

-vapor came out the top and bubbles were visible inside (boiling)

-as soon as the can was flipped into the ice water, it was crushed

-audible sound as the can was crushed Analysis:

Right before you flip the can into the freezing water, what is the vapor pressure of water inside the can?

The vapor pressure is high because increased temperature (boiling) means increased kinetic energy (the molecules

There is a drop in kinetic energy, so the vapor pressure inside of the can becomes extremely low. The drop in pressure means the molecules hit the sides of the can with less force and hit the sides less frequently. This made it possible for the higher atmospheric pressure outside to crush the can.

Describe what is happening to the molecules inside of the can during this process. How does that explain what happened to the can?

Before the can was placed into the ice bath, the temperature was very high. This meant that the vapor pressure was also high; the molecules were moving fast, hitting the sides of the can with a lot force and hitting the sides frequently. When the can was placed in the ice bath, the water molecules in the can quickly became liquid when the temperature changed. There was a drop in kinetic energy, so the vapor pressure inside of the can became extremely low. The drop in pressure meant that the molecules hit the sides of the can with less force and hit the sides less frequently. The pressure inside of the can was then much lower than the atmospheric pressure outside. The molecules outside crushed the can because when they hit the outside of the can, they hit it more frequently and with more force compared to the molecules inside of the

Bottom Chamber liquid:

Ethanol has a very low boiling point. When you heat the bottom chamber with your hand, the liquid molecules in the hand boiler increase in kinetic energy (increased temperature); the liquid expands. This rise in temperature causes the liquid to start to evaporate. Because there is some evaporation, but no condensation, the equilibrium is ruined in the hand boiler until the evaporated molecules lose kinetic energy and become liquid again (cool off).

Bottom Chamber gas:

When you apply heat to the bottom chamber, the gas increases in pressure because of the evaporated molecules. More molecules in a space means higher pressure. This higher pressure pushes the liquid up the tube to a lower pressure zone. The molecules hit the liquid with so much force and hit it so frequently that the liquid is forced into another area that has molecules that do not hit it so hard or so frequently.

Top Chamber