Computational chemistry is an integral part of the modern undergraduate chemistry curriculum because it can provide a visual approach to understanding structure and how it relates to function. Calculations can be used to understand topics such as molecular shape, chemical reactivity, along with predicting physical and chemical properties. This article describes three activities that were designed for use in General Chemistry Laboratory. In the first experiment, students use molecular modeling to relate geometry to Lewis structures of six simple molecules. This allows them to understand how the presence of lone pairs in Lewis structures affects molecular shape, and to compare the results predicted from classical and quantum mechanical bonding theories. They also display the dipole vector and map the electrostatic potential to better understand polarity. The second experiment is divided into three parts. In the first part, students build an ammonia molecule, and then do an optimization calculation using each of the three levels of theory. In the second part students relate carbon-carbon bond length to total energy for three hydrocarbons. In the final part, students explore carbon monoxide and molecular oxygen acting as ligands binding to iron. In the third experiment, the maximum electrostatic potential is used to predict the pKa of two acids. These three experiments can be incorporated into a general chemistry course, either as a group or individually, depending upon needs of the department and the needs of the student population.
Ivey et al. (Mon,) studied this question.