Pressure-Temperature Relationship in Gases. By Brian Su, Andrew Wang, and Gabriel Lee. Through this lab, the students observed the relationship between. Pressure will be monitored with a Gas Pressure Sensor and temperature will Determine from the data and graph, the mathematical relationship between . If this relationship is direct, k = P/T. If it is inverse, k = P•T. Based on your answer to . The notion that there is an ultimately lowest temperature was suggested by the behaviour of gases at low pressures: it was noted that gases seem to contract.
So we do is we think of the average energy of the particles. And the average energy of the particles, you might say oh, Sal is about to introduce us to a new concept. It's a new way of looking at probably a very familiar concept to you.
Temperature can and should be viewed as the average energy of the particles in the system. So I'll put a little squiggly line, because there's a lot of ways to think about it. And mostly kinetic energy, because these particles are moving and bouncing. The higher the temperature, the faster that these particles move.
Absolute zero | temperature | barcelonatraveller.info
And the more that they're going to bounce into the side of the container. But temperature is average energy. It tells us energy per particle. So obviously, if we only had one particle in there with super high temperature, that's going to have less pressure than if we have a million particles in there.
Let me draw that. If I have, let's take two cases right here. One is, I have a bunch of particles with a certain temperature, moving in their different directions.
And the other example, I have one particle.
And maybe they have the same temperature. That on average, they have the same kinetic energy.
- Gay-Lussac's Law Temperature-Pressure Relationship in Gases and the Determination of Absolute Zero
- Ideal gas equation: PV = nRT
The kinetic energy per particle is the same. Clearly, this one is going to be applying more pressure to its container, because at any given moment more of these particles are going to be bouncing off the side than in this example. This guy's going to bounce, bam, then going to go and move, bounce, bam.
So he's going to be applying less pressure, even though his temperature might be the same. Because temperature is kinetic energy, or you can view it as kinetic energy per particles. Or it's a way of looking at kinetic energy per particle. So if we wanted to look at the total energy in the system, we would want to multiply the temperature times the number of particles. And just since we're dealing on the molecular scale, the number of particles can often be represented as moles.
Remember, moles is just a number of particles. So we're saying that that pressure-- well, I'll say it's proportional, so it's equal to some constant, let's call that R.
Because we've got to make all the units work out in the end. I mean temperature is in Kelvin but we eventually want to get back to joules. So let's just say it's equal to some constant, or it's proportional to temperature times the number of particles. And we can do that a bunch of ways. But let's think of that in moles.
If I say there are 5 mole particles there, you know that's 5 times 6 times 10 to the 23 particles. So, this is the number of particles. This is the temperature. And this is just some constant.
Now, what else is the pressure dependent on? We gave these two examples. Obviously, it is dependent on the temperature; the faster each of these particles move, the higher pressure we'll have. It's also dependent on the number of particles, the more particles we have, the more pressure we'll have. What about the size of the container? The volume of the container. If we took this example, but we shrunk the container somehow, maybe by pressing on the outside. So if this container looked like this, but we still had the same four particles in it, with the same average kinetic energy, or the same temperature.
So the number of particles stays the same, the temperature is the same, but the volume has gone down. Now, these guys are going to bump into the sides of the container more frequently and there's less area. So at any given moment, you have more force and less area.
So when you have more force and less area, your pressure is going to go up. So when the volume went down, your pressure went up. So we could say that pressure is inversely proportional to volume. So let's think about that. A graph may be plotted to show how the pressure of a fixed mass of gas varies as the temperature is changed.
The temperature at which the pressure of an ideal gas would, in theory, reach zero can be determined by extrapolating the pressure vs. This temperature is referred to as absolute zero and is the zero point for the Kelvin temperature scale. An extrapolation to zero pressure is necessary because real gases condense to liquids and solidify before reaching absolute zero. In this experiment, the pressure within the Absolute Zero Demonstrator apparatus is measured at several different temperatures.
A graph of pressure vs. The apparatus consists of a copper bulb having a fixed volume copper expands and contracts only slightly with temperaturea pressure gauge, and a fixed mass of gas. Gas pressure is measured with the pressure gauge. Before a measurement is taken, the apparatus is allowed to equilibrate to ensure that the gas and bulb are at the same temperature.
Do not use open flames during the experiment. Ethanol and acetone are very flammable. Dry ice and liquid nitrogen should be handled very carefully wear safety glasses and insulated thermal gloves due to the risk of frostbite.
Never put dry ice or liquid nitrogen in a closed container because each will build up pressure and explode the container. Wear safety glasses during the experiment.
Use insulated thermal gloves and appropriate care when handling the water baths, dry ice, liquid nitrogen, and Absolute Zero Demonstrator. Procedure All participants put on safety glasses. Individuals responsible for handling the Absolute Zero Demonstrator apparatus, water baths, dry ice, and liquid nitrogen put on insulated thermal gloves.
Support the apparatus with a large 3-prong clamp and clamp holder and support the thermometer with a small 3-prong clamp and clamp holder. Allow the water to return to a full boil. Wait a few minutes for the apparatus to equilibrate.