LAB #14: HESS'S LAW

Experiment Summary

The purpose of this investigation is using Hess's Law to calculate the enthalpy of reaction of:

The equations that will be use to "add up" to get the above equation include:

The lab component is to determine experimentally the enthalpy of reaction for A AND then for reaction B, and then with that information mathematically calculate the enthalpy of formation for MgO.

Experimental Set-up

The following video provides the concept of the lab that you are going to do. Please make sure that you follow our written procedure provided to you, which is also posted below. Please take note of the following that we will NOT do which was described/demonstrated in the video:

  • try NOT to poke around with a glass stirring rod.
This is a long video but it goes through everything line by line.

Procedure

View the procedure handout attached at the bottom of this page. Please note that we will not look at the kinetics of crystal violet, but of another, very similar molecule. The principles operate similarly to the discussion above. Apply what you learned about crystal violet to the molecules and reactions under investigation.