1. Navigate to https://phet.colorado.edu/en/simulations/reversible-reactions/activities. Works best if run in Microsoft Edge.
2. Click on the image at the top and Run CheerpJ Browser-Compatible Version
the platform on the left and the enthalpy of the product molecules for the right platform. The ruler in the center represents something called the activation energy, which is the energy needed to convert the molecules between reactants and products. If you focus on the blue line that runs across the platforms and ruler, you can see that the height of the hill in the center is different going from left to right than it would be going right to left.3. Once the simulation opens, the items that you will be moving are the height of the left side and right side gray platforms and the ruler in the center. The heights of these sections represent the enthalpy of the reactant molecules (for ΔHreaction)
4. Adjust the heights of the two platforms and the ruler in the center as follows: pick the set of conditions that correspond to the first letter of your last name
A-G) left = 15, right = 20, ruler to 30
H-L) left = 20, right = 15, ruler to 30
M-S) left = 10, right = 15, ruler to 30
T-Z) left = 15, right = 10, ruler to 30
5. Make sure that the temperature at the right is set to 500 Kelvin. You will not need to show species information or energy histograms. You also will not be using the heat control at the bottom.
.6. Enter 300 for the number of molecules of A, do not press enter- press START, then play in the chamber and leave B set to 0. A is your reactant and B is the product, so your equilibrium is A(g)⇌B(g).
7. Open a blank Excel file. In A1, type “time (s)”, in B1 type “reactants”, and in C1 type “products”. You can fill in lines A2, B2, and C2 with 0, 300, and 0, since that will be your starting amounts of each substance at time = 0 seconds.
8. Go back to the simulation. You will press start at the bottom of the screen, then pause the simulation approximately 20 seconds later. Do not click "STOP".
9. Record the time, to the nearest second, and the number of molecules of A and B. You can find the number of each molecule either below the platform or in the top right corner of the simulation. Transfer these values into the next row in Excel.
10. Resume the simulation by hitting the play button again and pause after another 20 seconds have passed. Once again, transfer your time and molecules into your spreadsheet.
11. Repeat step 10 until you have reached 300 seconds. After you reach 300 seconds, take data points every 30 seconds until you have reached 600 seconds total. After you reach 600 seconds, take data points every 60 seconds until you have reached 900 seconds total.
12. Click “reset” on the right side of the simulation. Back in Excel, in columns E1, F1, and G1, type the same headings that you used in boxes A1-C1.
13. With 0 molecules of A and 300 molecules of B, repeat steps 8-11, placing your data in columns E-G.