Lab 13 - Absolute Zero  Group Members

Miami University Physics Worksheet

 

Lab 13: Absolute Zero 

Group Members:

Section Letter:                                         

Introductory Videos:

Absolute Zero Up till 2:40

Absolute Zero Lab

Temperature Scales and Conversions | Celsius, Fahrenheit, and Kelvin

Use the video below to answer questions 1-2.

Temperature Scales and Conversions | Celsius, Fahrenheit, and Kelvin

 

Questions:

1. If the freezing point of a liquid is 2.9°C, what is it’s freezing point in °F? Show your work on a notebook and paste it here. You must show your work to get credit.

2. The temperature of an object A is 75K, and that of another object is 23°F. Which object has a higher temperature value? (Hint: convert both temperature values to °C and compare) Show your work on a notebook and paste it here. You must show your work to get credit.

Answer questions 3-5 using the interactive simulation in the link below:

Simulation of Gas Properties

Instructions: Click on the tab “Ideal”. Lift the pump up and down to release gas particles into the container. Change the pressure scale to KPa. KPa (kilopascals) is a common unit of pressure. Pay attention to the pressure and temperature values, as well as the motion of the gas particles.

3. Raise the temperature (from 300K to about 2000K) by applying heat to the container. What happens to the motion of the gas particles as you increase the temperature?

4. Cool the container (back to around 300K). How does the pressure change with temperature?

5. Now, cool the container to 0K (zero Kelvin). What is the gas pressure at this temperature? What is the motion of the gas particles at this temperature?

The video below demonstrates the procedure for determining absolute zero. This procedure is similar to what we would have done in the lab. Follow the steps taken in the video and record your data set in the table below. Note that the pressure values were measured in mmHg, but we will be working in kilopascals (KPa). To convert to KPa, multiply the value in mmHg by 0.1333. That is, 1mmHg = 0.1333KPa.

Absolute zero lab demonstration

Data:

Type of Bath Used

Temperature (°C)

Pressure (mm Hg)

Pressure (KPa)

Room temp. water

Boiling water

Warm water

Ice water

Liquid nitrogen

Questions:

6. Prepare a graph of pressure vs. temperature and fit it to a straight line using Excel. Include your graph here. Make sure it has proper labels and units, and the equation is shown on the graph. Also, please make the graph large enough to be easily read.

Instruction on how to fit your graph in Excel: After plotting your graph, right click on the straight line. Select “Add Trendline” Trendline options show up at the right hand side of the screen. Scroll down and click on the box with “Display Equation on chart”. You will see an equation on your graph.

7. Are pressure and temperature directly or inversely related? Justify your answer based on your graph.

8. From the equation on your graph, determine absolute zero. To solve for the value of absolute zero, use the equation for a line, y = mx + b. Absolute zero is the temperature at which the gas’s pressure (y, in the equation) equals zero. This is the line’s x-intercept. To calculate this value, set y = 0, and solve for x from your graph equation.

9. Use the internet to check for the expected value of absolute zero. Is your answer in question 8 above the same as the expected value? If no, why do you think your answer turned out to be different from the expected value?

10. In comparing your answer (experimental value) with the expected value, what is your percent error for this value? You may find the equation below useful.

11. Why were we able to ignore V in the PV=nRT equation when calculating absolute zero?

12.Suppose the pressure in the gauge was measured in other absolute pressure units (say torr), how would that change your answer for absolute zero? Justify your response.