CH141 Laboratory



CH141 Lab Section




Experiment 8: Introduction to Physical and Computational Molecular Modeling


Use complete sentences. Use the proper number of digits and/or significant figures where appropriate, and include units. Erase all the words in italics and type your answers/information into this template (your text/answers shouldn’t be in italics).


Introduction: 2-sentence maximum; state the scientific purpose of the experiment. Describe the method you will use, in a general sense.


Procedure : Give a general and brief description of the experimental procedure, and include information about the computational packages (the computer programs) that you used. You do not have to describe the ball and stick modeling or the lab 8 worksheet (just the computer modeling part). Reference the experiment handout on the CH141 website. List any changes from the written procedure on the handout (if any).


Results : Tabulate your results for the computer modeling sections of Experiment 8 (Parts I-IV). Make sure to include a label(s) and table description(s). Also include the result of your dipole calculation using the equation on page 312 of your text.


Discussion : For this discussion section, answer the following questions in paragraph form.


         How does water compare to ammonia with respect to bond angles and dipole moments? Based on what you have learned in class, were any of the calculated values different than what you expected?


         What do you notice about the bond lengths in the nitrate and acetate ions and why are your observations significant in terms of chemical bonding?


         How does methane compare to chloromethane with respect to bond angles and dipole moments?


         Is the chlorination of methane exothermic or endothermic? How could that be explained in terms of chemical bonding?