Lewis Structures and Molecular Shapes Using VSEPR Quizzes
You can practice writing Lewis structures and determining both the electronic structure (sometimes called the electron-domain geometry) and the molecular structure (sometimes called the shape or the molecular geometry) for molecules. When you first press the "Quiz Me!" button, you will be given a molecule and asked to draw the Lewis structure. Unlike other online content by some publishers you can't draw the structure online and then submit it for a grade. You'll need to write it out yourself and then compare it to the structure shown after you press the "Reveal Lewis Structure" button. Your structure may not be drawn exactly like the one shown here so check your version for the number of lone electron pair and shared electron pair. Then you'll be able to choose both an electronic structure and a molecular structure for your species. I suggest you do this part before pressing the "Display Molecule" button since that should clearly show you the shape of the molecule!
You then have a number of different options and I urge you to play with the possibilities. For example, if you choose the "Theoretical Geometry" option you can then look at one or more theoretical vibrations. While we don't cover vibrations in my classes (probably not unless you take a class in physical chemistry), it is fun.
There are differences in how some Lewis structures are written with respect to formal charge. These molecules follow the guidelines discussed in my classes and some will not be minimized according to formal charge rules. For my classes, any assessment questions about formal charge will be clearly stated. If you are visiting this page from somewhere else and your professor/instructor requires all structures to be written with a minimum of formal charges, then you will see some differences in some Lewis structures.
127 possible molecules.
6/30/2014 Future expansion:
- Add polyatomic ions
- Allow the display of bond lengths and angles using a button select (this will allow it to be easily used on an iPad)
A page that discusses the use of JMol to visualize the molecules and some performance issues.
Podcasts on Lewis structures and VSEPR:
Some documents you might need:
- WebElements Periodic Table (I use the 5-figure version)
Polyatomic Ions- Table of Electronegativities
