Grahams Gas Law

GAS LAWS

KINETIC ENERGY/ GRAHAM’S LAW LAB

Chemistry

Block 8

April 20th, 2005

Purpose:

To observe how masses of atoms and molecules affect their rate of diffusion, and explain our observations in terms of mass, velocity, kinetic energy and temperature.

Warm-up Question:

1. What is the definition of temperature?

Temperature is a measure of the average Kinetic Energy of the particles composing a material.

2. What is the definition of diffusion?

Diffusion is a spontaneous spreading of particles until they are uniformly distributed in their container.

3. If we increase the temperature of sample of gas, then what about the gas molecules will have to change?

The gas molecules would begin to increase in speed since the temperature would increase.

4. The element iodine (I2) diffuses more slowly than ethanol (CH3CH2CH2OH). Why is this?

Iodine is heavier in atomic mass then ethanol, slowing down its process to diffuse. Iodine weighs 253.6u while ethanol weighs 60.03u, giving ethanol a faster diffusions rate.

Procedure A:

1. Obtain a glass tube and wash it with water. Dry the outside of the tube with a paper towel. Next, squirt some acetone into the tube. A small amount is all that is needed. Then dry the inside of the tube by passing air through the tube (use a fan, the window, blow through it, etc.)

2. Use chalk to label one end of your lab station, "HC1," and the other end, "NH3."

3. Lay the glass tube on the table and place the thermometer on the table next to the tube.

4. !!!CATION!!! THE NH3 AND THE HCI ARE IN VERY CONCENTRATED FORMS. DO NOT ALLOW EITHER CHEMICAL TO COME INTO CONTACT WITH YOUR SKIN. IF THE NH3 OR HCl SPILLS, GET A DAMP PAPER TOWEL AND CLEAN IT UP IMMEDIATELY!!!

5. Obtain 1 small bottle of HCI and 1 small bottle of NH3. Place each bottle in their respective ends of the lab table. Obtain forceps, label them, "HC1" or “NH3"with tape, and place them at their respective end of the lab table.

6. Record the temperature of the air around the tube in the data table.

7. Separate