Name : Phillip Radel Date: 2/6/15

Boyles’s Law Lab

CHEMISTRY B

Introduction:

Boyle’s Law explains the relationship between the pressure and volume of an ideal gas when the temperature and amount of gas inside a container remain constant. The purpose of this lab is to investigate the relationship between the volume of a container and pressure of the gas inside the container. You will observe what happens to pressure when volume is changed.

Procedure

1. Open the simulation by clicking on “Run Now.”

2. Click on the “Measurement Tools” button. Select “Ruler.” This will cause a ruler to appear. Place the ruler horizontally across the bottom so the zero mark aligns with the left edge of the box.

3. The units on the ruler are in nanometers (nm). Look at the graduations on the ruler. What does each graduation represent? Each graduation on the ruler represents a fifth of a nanometer.

4. The ruler will be used to estimate the volume of the container. Volume is measured in liters (L). Throughout the activity, use the ruler to measure the width of the box in nanometers (nm). However, in the data table, record the unit of measurement as liters (L). For example, if you measure the width of the box as 6.6 nm, you would record a volume of 6.6 L in the data table.

5. Click on the Temperature button under "Constant Parameter” at the righthand side of the screen.

6. Look at the “Gas in Pump” menu under the pump. Be sure that the Heavy Species of gas is selected.

7. Pump approximately 1 atmosphere (atm) of pressure inside the box. (For this simulation, 1 atm is equal to 200 particles. You may type 200 directly into “Heavy Species.”)

8. What is the temperature inside the box? The temperature is around 300k.

9. Adjust the volume of the box by dragging the handle left or right. Allow the temperature to return to its initial value. Move the ruler to measure the size of the box. Record this value in the Heavy gas species table in the volume column. Record the pressure in atmospheres (atm) in the pressure column.

10.. Repeat this process, selecting various volumes, until you have four data values.

11. Click the “Reset” button.

12. Locate the “Gas in Pump” menu and click on Light Species.

13. . Repeat the experiment with the light gas species.

Once you have completed the virtual lab, answer all of the questions below. Refer to the rubric to make sure you include all of the necessary components. You will submit your work to your teacher.

Analyze

1. Using spreadsheet software, create a line of best fit graph of the data of the heavy gas species and a graph of the data of the light gas species. Label the x-axis Volume (L) and the y-axis Pressure (atm). Give the graphs appropriate titles.

2. Based on the data, as the volume gets larger, what happens to the pressure of the gas?

As the volume of the container increases, the pressure inside decreases, and as the volume of the container decreases, the pressure inside the container increases.

3. Look up Boyle’s Law in a science textbook. How do the results of the experiment support or contradict Boyle’s Law?

The evidence of the experiment supports the law because if the trapped air was compressed, then the pressure inside increased and the container was downsized.

4. Go back to the data tables. Multiply the pressure and volume pairs to calculate the values of k. Record values in the data table. Good data may show minor variations, but the values for k should remain relatively consistent.

a. What is the average value of k for the heavy gas species? Around 0.503

b. What is the average value of k for the light gas species? Around 4.006

c. How does the molecular weight of the gas affect the k value? The lighter the molecule, the higher the k value.

5. Based on the results of this lab, develop a hypothesis to explain why bubbles exhaled by scuba divers grow in size as they reach the surface of the ocean

At the bottom of the ocean, the pressure containing the bubbles is high as the air reaches the surface, the force of the water molecules has less compression against the gas and allows the bubbles to expand and grow in size.