Pouring liquid nitrogen onto a balloon decreases the volume of the balloon dramatically. Afterward, the balloon re-inflates. Use kinetic theory to explain this sequence of events. The temperature of liquid nitrogen is -196 degrees Celsius
The molecules of air within the balloon move at increasing speeds as temperature rises. These particles continuously bombard the walls of the balloon and that causes the balloon to inflate. At lower temperatures the molecules have much less energy so the balloon is deflated. Take this information, expand on it, and write your answer.
When liquid nitrogen is poured onto a balloon, the extremely cold temperature causes a decrease in the volume of the balloon. This can be explained using the principles of kinetic theory.
Kinetic theory states that all matter is made up of tiny particles (atoms or molecules) in constant motion. The speed of the particles is directly related to their temperature - the lower the temperature, the slower the particles move.
When liquid nitrogen, at a temperature of -196 degrees Celsius, comes into contact with the balloon, the cold temperature causes the particles in the air inside the balloon to slow down and lose energy. As the particles lose energy, they move closer together, decreasing the volume of the balloon.
However, as the liquid nitrogen evaporates, it begins to warm up and reach room temperature. The nitrogen gas molecules in the air inside the balloon start gaining energy and their speed increases. This increase in molecular motion leads to an increase in pressure inside the balloon, causing it to reinflate.
In summary, the initial decrease in volume of the balloon occurs because the cold temperature slows down the air particles inside it. As the liquid nitrogen evaporates and warms up, the air particles regain their energy and increase in speed, causing an increase in pressure and leading to the reinflation of the balloon.
To understand why liquid nitrogen poured onto a balloon decreases its volume and then causes it to re-inflate, we can delve into the principles of kinetic theory.
Kinetic theory states that all particles in a substance are in constant motion. The motion of particles is directly related to temperature: as temperature increases, the average kinetic energy of the particles also increases. At extremely low temperatures, such as -196 degrees Celsius for liquid nitrogen, the particles' motion slows down significantly.
Now, let's apply this theory to the process of pouring liquid nitrogen onto a balloon:
1. Decrease in Volume: When liquid nitrogen, with its extremely low temperature, comes into contact with the surface of the balloon, it transfers its thermal energy to the air molecules inside the balloon. As a result, the temperature of the air inside the balloon rapidly decreases.
2. Decreased Particle Motion: When the temperature decreases, the average kinetic energy of the air molecules decreases as well. This reduction in kinetic energy causes the air molecules to slow down and move with less force. Consequently, the pressure exerted by the air inside the balloon decreases.
3. Balloon Deflation: As the pressure inside the balloon decreases due to the reduced kinetic energy of the air molecules, the balloon's elastic structure contracts inward, causing a decrease in volume. This is why the balloon appears to deflate when liquid nitrogen is poured onto it.
4. Re-Inflation: After some time, the liquid nitrogen evaporates and converts into a gas, which then mixes with the air inside the balloon. The gas molecules from the evaporated liquid nitrogen have a much higher kinetic energy compared to the cooled air inside the balloon. Consequently, the average kinetic energy of the particles inside the balloon increases, causing them to move with more force.
5. Increased Particle Motion and Pressure: As the kinetic energy of the gas molecules increases, their motion becomes more vigorous, and the pressure inside the balloon rises. This increase in pressure pushes against the walls of the balloon, causing it to re-inflate.
In summary, pouring liquid nitrogen onto a balloon causes the air inside the balloon to cool down due to the transfer of thermal energy. This results in a decrease in the kinetic energy and pressure of the air molecules, causing the balloon to deflate. However, as the liquid nitrogen evaporates, the higher kinetic energy of the gas molecules causes the pressure inside the balloon to increase, thereby re-inflating it.