Step 1: Find valence e- for all atoms. Add them together.

P:5

C:7x5=35

Total=40

Step2: Find octet e- for each atom and add them together.

P:10*

Cl:8x5=40

Total=50

Phosphorous gets 10 electrons since it should make 5 bonds with surrounding atoms.

Step3: Gives you bonding e-. Subtract step 1 total from step 2

50-40=10e-

Step 4: Find number of bonds by diving the number in step 3 by 2(because each bond is made of 2 e-)

10e-/2= 5 bond pairs

Step 5: Find the number of nonbonding (lone pairs) e-. Subtract step 3 number from step 1.

40-10= 30e-=15 lone pairs

Use information from step 4 and 5 to draw the lewis structure.

## Lewis dot structure of PCl5_{}

Alternatively a dot method can be used to draw the lewis structure.

Calculate the total valence electrons in the molecule.

P:5

C:7x5=35

Total=40

Put put phosphorous in center and chlorines on sides.

Put a pair of electrons connecting the side atom with central atom.Put remaining electrons on the side atoms.