Week 8 Reflection

During chemistry class this past week, we continued our discussion of pressure vs. the changing factors of a system. In a direct pressure vs. particles system, doubling the number of particles always doubles the pressure because the have a constant ratio. Pressure is equal to the number of particles multiplied by a pressure to particle ratio. In a directly proportinal pressure vs. temperature relationship, it was odd to see the beginning of the line of the graph not start at zero, which aroused the question, do particles still move at 0 kilopascals? Though particles are still moving at 0 degrees Celsius, is there still a temperature that all particles stop moving at? It was then revealed to us that after many tests and multiple researches done on this topic, that there was an "absolute zero". This "absolute zero" is -273.15 degrees Celsius or 0 Kelvin.

This week, we were introduced to the concept of a third temperature scale: Kelvin (whose units are the Kelvin). From here, we were able to determine that while Celsius is relative to water, Kelvin is the absolute scale. When dealing with Kelvin from now on, it was agreed upon that instead of starting our graphs at zero, we would start our graphs at absolute zero, or -273.15 degrees Celsius. We then established rules for converting tempertures after noticing certain patterns in our data: degrees Celsius ---> Kelvin = degrees Celsius + 273.15; Kelvin ---> degrees Celsius = Kelvin - 273.15; degrees Celsius ---> degrees Fahrenheit = 2(degrees Celsius) + 32.

Another discussion in class involved two full 2 L bottles of water each with a tube with on a rubber stopper on top. One tube has a sealed tip, while the other's tip was unsealed. As you squeezed the sides of both bottles, you could see the pressure building up inside the bottle as it forced water up the tubes, causing them both to sink. The only difference between the two was that sealed tip tube didn't stay sunk and bounced back up. While each tubes mass stayed the same, the volume increased inside the sealed tip tube, causing it to bounce back up after hitting the bottom of the bottle becauses it was less dense. The unsealed tip tube stayed at the bottom of the bottle because its volume had decreased, which then caused its density to increase and not allow it to float.