Experiment and Tutorial #40 The Great Escape Part 1 Draft 5.28.01

Part 1. Data Collection. Web simulation #40.

In this experiment, a syringe is filled with a gas. The syringe has markings on it to indicate the volume (in cm³) of the gas in the syringe. You can choose the gases you wish to investigate from the menu of available gases. In this experiment, the initial temperature of each gas will be set at 298K. You can measure the pressure of the gas. You can measure the mass of the gas. The syrnge is plunged into an evacuated flask (a flask with no air or other gas in it - a vacuum) and the gas starts to escape from the end of the needle into the evacuated flask. You can time how long it takes for the piston to move from the starting point (300.0 cm³ ) to a point lower on the syringe (25.0 cm³ ).

 For this first set of experiments, we suggest that you keep the initial temperature of each gas at 298K and the initial pressure of each gas at 1.00 atm.

Here are several questions for you and your group to investigate:

How will you measure the time it takes for a gas to escape? How will you determine the rate of escape of a gas?

What is the dependent variable in your experiment? What are the independent variables in your experiments?

Of the gases available to investigate: Which gas escapes from the syringe fastest? Which gas escapes from the syringe slowest? Explain what you mean by fastest.

How is the molecular weight of a gas related to the time it takes for it to escape? Graph.

How is the density of a gas related to the time it takes for it to escape? Graph.

How is the rate of escape of a gas related to its molecular weight? Graph.

Data for Experiment #40 The Great Escape

Gas	MW	Time (sec)
hydrogen	2.0000	1.5000
helium	4.0000	2.1200
methane	16.000	4.2400
oxygen	32.000	6.0000
sulfur dioxide	64.000	8.4800
hydrogen iodide	128.00	12.000