Chapter 1.6, Problem 1.68MP

Interpretation Introduction

Interpretation:

All the lone pairs that is present in the given structure has to be drawn.

Concept Introduction:

Lone pair of electrons are the pair of valence electrons that are not involved in bonding with other atoms.  These are also called as non-bonding pair.  Formal charge and lone pair of electrons are more important in representing a correct structure.  If we know the formal charge on an atom, the lone pair of electrons can be found and vice-versa.  The simple convention is to ignore the lone pairs and always show the formal charge.  To find the lone pair of electrons present on an atom, few steps has to be followed and they are listed below,

• Valence electron of an atom has to be found according to the periodic table.
• Formal charge on the atom has to be considered.  Positive charge means one electron less and a negative charge means one electron is more.
• The difference between the valence electron and the formal charge gives the lone pair of electrons that is present.

If the compound contains carbon atom and there is no formal charge present on the carbon atom means it will have four bonds and no lone pair of electron.

If the carbon atom has a formal positive charge means, then the carbon atom will have three bonds and no lone pair of electrons.

If the carbon atom has a formal negative charge means, then the carbon atom will have three bonds and one lone pair of electrons.

If the compound contains nitrogen atom and there is no formal charge present on the nitrogen atom means it will have three bonds and one lone pair of electron.

If the nitrogen atom has a formal positive charge means, then the nitrogen atom will have four bonds and no lone pair of electrons.

If the nitrogen atom has a formal negative charge means, then the nitrogen atom will have two bonds and two lone pair of electrons.

If the compound contains oxygen atom and there is no formal charge present on the oxygen atom means it will have two bonds and two lone pair of electrons.

If the oxygen atom has a formal positive charge means, then the oxygen atom will have three bonds and one lone pair of electrons.

If the oxygen atom has a formal negative charge means, then the oxygen atom will have one bond and three lone pair of electrons.