McMurry (Kap 2,3)

Question 1

What is formal charge on an atom?

Answer 1

Don’t imply the presence of actual ionic charges in a molecule, rather it is a device for electron bookkeeping for a atom.

When each atom donates one electron, a bond is formed (each atom still owns one electron for bookkeeping purposes), and therefore are neutral.

But when the numbers of electrons an atom donates is more then usual/ or less, charge is put on an atom.

Question 2

How is formal charge calculated?

Answer 2

The number of valence electrons for an atom - (bonding valence electrons/2 + nonbonding valence electrons)

Question 3

When an atom have more bonding’s then normal, does it have a (positive formal charge or negative?)

Answer 3

When an atom have more bonding’s then usual, more of its electrons are being given away for the bonding purposes leaving the atom more positive (positive formal charge).

Less bonding’s then usual means more negative formal charge.