Question

Draw the best Lewis structure for CH 3 -1. What is the formal charge on the C?

Answer 1

Answer :  The formal charge on the C is, (-1) charge.

Explanation :

Lewis-dot structure : It shows the bonding between the atoms of a molecule and it also shows the unpaired electrons present in the molecule.

In the Lewis-dot structure the valance electrons are shown by 'dot'.

The given molecule is, $CH_3^{-1}$

As we know that carbon has '4' valence electrons and hydrogen has '1' valence electron.

Therefore, the total number of valence electrons in $CH_3^{-1}$ = 4 + 3(1) + 1 = 8

According to Lewis-dot structure, there are 6 number of bonding electrons and 2 number of non-bonding electrons.

Now we have to determine the formal charge on carbon atom.

Formula for formal charge :

$\text{Formal charge}=\text{Valence electrons}-\text{Non-bonding electrons}-\frac{\text{Bonding electrons}}{2}$

$\text{Formal charge on C}=4-2-\frac{6}{2}=-1$

The formal charge on the C is, (-1) charge.