Crushing Can:
youtube video:
/watch?v=SBpqT-u8sjo
1. Explain why the can collapsed using the Combined Gas Law where T1 is the initial temperature of the air inside the can before the can was inverted and T2 is the temperature of the air inside the can after it was plunged into the ice water.
2. Why did the can need to be inverted?
3. Adding water to the can and boiling it pushes the air molecules out of the can. Why is this step needed?
1. The Combined Gas Law states that the pressure of a gas is directly related to its temperature. When the can is initially filled with air at a certain temperature (T1), it also contains a certain amount of gas molecules. When the can is inverted and placed in ice water, the temperature of the air inside the can decreases (T2). According to the Combined Gas Law, as the temperature drops, the pressure of the gas inside the can also decreases.
As a result, the pressure difference between the inside and outside of the can increases. The atmospheric pressure outside the can remains constant, but the lower pressure inside the can causes the can's walls to collapse inward. This is because the external pressure is greater than the internal pressure, exerting a net force on the can that causes it to collapse.
2. The can needs to be inverted before placing it in ice water to ensure that the air inside the can is completely replaced with water vapor. By turning the can upside down, the opening of the can is submerged in the water, allowing the water to flow inside. This is important because when water is heated, it evaporates and fills the can with water vapor, displacing the air. Inverting the can ensures that the air is replaced entirely with water vapor, which will produce the desired effect when the can is later cooled down.
3. Adding water to the can and boiling it serves the purpose of driving out the air molecules from the can. When the water is heated and begins to boil, it creates steam within the can. The expanding steam pushes the remaining air molecules out of the can through the opening or the process of displacement. By removing the air and replacing it with steam, we are effectively creating an environment where there is only water vapor inside the can when it is inverted and submerged into the ice water. The absence of air molecules inside the can is crucial because it allows for a greater pressure difference to occur between the inside and outside of the can when it is cooled down, resulting in the collapse of the can.