5-2: Charles’ Law: Temperature and Volume
Charles’ Law was discovered by Joseph Louis Gay-Lussac in 1802; it was based on unpublished work done by Jacques Charles in about 1787. Charles had found that a number of gases expand to the same extent over the same 80 degree temperature interval. You will be observing the relationship between the temperature and volume of a gas similar to that studied by Charles and making inferences based on analyzing the data that you collect.
- Start Virtual ChemLab, select Gas Properties, and then select Charles’s Law: Temperature and Volume from the list of assignments. The lab will open in the Gases laboratory.
- Note that the balloon in the chamber is filled with 0.050 moles of an ideal gas (MW = 4 g/mol) at a temperature of 100.00 C, a pressure of 1.000 atm, and a volume of 1.531 L. To the left of the Temperature LCD controller is a lever that will decrease and increase the temperature as it is moved up or down; the digit changes depending on how far the lever is moved up or down. Digits may also be clicked directly to type in the desired number, or they can be rounded by clicking on the R button. You may want to practice adjusting the lever so that you can decrease and increase the temperature accurately. Make sure the moles, temperature, and pressure are returned to their original values before proceeding.
- Increase the temperature from 100.00 C to 1000.00 C in 100 degree increments. After each increment, record the volume, pressure, temperature and number of moles in the data table below.
Data Table: Ideal Gas (MW = 4 g/mol)
Number of moles (n)
- Open the MS-Excel file “Charles_Law_Plot_Ideal_Gas”. Enter your data into the data table spaces in the Excel file as appropriate. It will automatically generate a graph of Volume (L) vs Temperature (C). The graph will feature a best-fit straight line with an equation and quality of fit (R value). The line will be extrapolated backwards until it crosses the x-axis. Save this file for submission along with this worksheet.
- Based on your graph, qualitatively describe the relationship between the temperature and the volume of a gas (assuming a constant pressure and moles of gas)?
- Using the equation of the best-fit straight line obtained from your graph, calculate the temperature at which the gas will have zero volume. Show your work here. Give your final answer to 2 decimal places.
- What is the significance of the temperature at which the gas will have zero volume? What is the accepted value for this temperature?
- A sample of gas occupies 0.500 L at 1.000 atm and 0.00 C. What is the pressure of the gas, in lb/in2, if it is at 85.0 C and occupies 945 mL? Show your work for full credit.