Practice with skeletal structures and molecular geometry

This is an extremely helpful exercise that all orgo students should be able to do. Answers are included in a second graphic below the first.

Below are several skeletal structures. Redraw the skeletal structures with all their hydrogens in the correct geometry, I.E. tetrahedral for sp3 hybridized atoms, trigonal planar for sp2 and linear for sp. Don’t draw wedges or dashes coming off of other wedges or dashes. It gets too crazy if you try to do that. When required, also redraw the structure so that all bonds are drawn with correct geometry.

Also add lone pairs so that each atom has the correct formal charge. When indicated, assign formal charge to the atom in the structure that most likely bears the charge. Don’t draw radicals for this exercise, I.E. do not draw atoms with unpaired electrons. Only draw atoms with zero, one or more lone pairs.

There are two versions of the graphic: one to practice on and one with answers. In many cases there is more than one possible correct answer because single bonds can rotate. In some cases there may be an ideal geometry you should be drawing: for example staggered conformations around adjacent sp3 atoms. In other cases you probably won’t have enough information to know what the best conformation is; just make a guess and don’t worry too much if it doesn’t match my answers exactly.






Here are the answers!