Commonly Tested Lewis Structures

We draw Lewis Structures to predict:

-the shape of a molecule.

-the reactivity of a molecule and how it might interact with other molecules.

-the physical properties of a molecule such as boiling point, surface tension, etc.

Drawing the Lewis Structure for PCl₅

Video: Drawing the Lewis Structure for PCl₅

For the PCl5 Lewis structure we first count the valence electrons for the PCl5 molecule using the periodic table. Once we know how many valence electrons there are in PCl5 we can distribute them around the central atom and attempt to fill the outer shells of each atom.

There are a total of 40 valence electrons in the PCl5 Lewis structure.

Remember when you draw the Lewis structure for PCl5 that Phosphorous (P) is in Period 3 on the Periodic table. This means that it can hold more than 8 valence electrons.

For the Lewis structure for PCl5 you should take formal charges into account to find the best Lewis structure for the molecule.

It is helpful if you:

• Try to draw the PCl₅ Lewis structure before watching the video.
• Watch the video and see if you missed any steps or information.
• Try structures similar to PCl₅ for more practice.

List of Lewis Structures

Acetone	BF3	BH4-	BrF5	BrO3-	C2H2	C2H4	ClO-
CH4	ClO2-	ClO2	ClO4-	CO	CS2	H2O	H3O+
HCl	HNO3	I3-	ICl4-	IF5	N2	N3-	NH2OH
NH3	NO2-	NO2	NO3-	O2	OF2	PCl5	PH3
PO33-	PO43-	SCl2	SF4	SF6	SO3	SO42-	XeF2
XeF4