Preview - Energy In Chemical Reactions

Behavior of the Overall System

The simulation you were working with models dissolving KI in water. You have control over the exact number of water molecules represented in the “beaker”. You will begin by looking at the overall bulk system.

 

Directions:

  • Adjust the slider bar to the maximum number of water molecules possible. Then press "setup". Press "go" and observe the water molecules moving around the beaker in liquid form.
  • Now press “add KI” and observe what happens to the ionic compound and the temperature of the beaker.
  • Allow the simulation to run until all KI is split into K+ cations and I− anions.
  • You may repeat the procedure as needed to answer the questions below.

Questions

Please answer the questions below.

Calculate the change in temperature of the system by recording the initial and final temperatures of the system below. (Hover your cursor over the graph to obtain exact initial and final temperatures.)

What action in the simulation corresponds to the specific temperature drops shown on your graph? If you are not able to determine this, reduce the number of water molecules until you are able to observe how the molecular motion of both the water molecules and the ionic compound corresponds to the temperature drop.

Notes

These notes will appear on every page in this lesson so feel free to put anything here you'd like to keep track of.