1.4: Experiment 3 - Molecular Shape
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By the end of this lab, students should be able to:
- Draw the Lewis Dot structures for molecules that obey the octet rule.
- Draw resonance structures for molecules that obey the octet rule.
- Draw Lewis Dot structures and resonance structures for molecules that don't obey the octet rule.
- Calculate the formal charges of individual atoms within a molecule.
- Predict the electron geometry and molecular shape of individual molecules using VSEPR theory.
- Interpret the AXE notations and apply this knowledge when using the VSEPR theory.
- Distinguish between polar and nonpolar molecules.
Molecular compounds are formed when two non-metals share valence electrons forming a covalent bond. This results in two types of orbitals; bonding orbitals, where the valence electrons are shared between two nuclei, and non-bonding orbitals (lone pairs), where the valence electrons are localized to one nucleus. Molecules have definite geometric shapes which influence their chemical properties and behavior. The first step in understanding a molecule's geometry is in determining the connectivity of the atoms, and the types of orbitals each atom possesses. This can be conveniently done with Lewis dot structures, which account for all valence electrons by using lines between atoms to represent bonding electron pairs and dots to represent lone electrons.
Lewis Dot Structure Worksheet
Use the PHET simulation (CC-BY-4.0) below to complete the Worksheet. The document below is a preview only.
Molecular Shape Worksheet
Use PhET Simulation to complete the Molecular Shape Worksheet. This document is a preview only.
Contributors and Attributions
Robert E. Belford (University of Arkansas Little Rock; Department of Chemistry) led the creation of this page for a 5 week summer course.
Elena Lisitsyna contributed to the creation and implementation of this page, including generation of the HP5 questions.
- Mark Baillie coordinated the modifications of this activity for implementation in a 15 week fall course, with the help of Elena Lisitsyna and Karie Sanford.