Question

Determine the formal charge of oxygen in the following structure. If the atom is formally neutral, indicate a charge of zero.

 

(b)Draw an alternative Lewis structure for the compound given in part (a). Show the unshared pairs and nonzero formal charges in your structure. Don't use radicals.

Answer 1

Concepts and reason

According to octet rule, each atom forms bonds with other atoms until it gets eight electrons in its valence shell. The Lewis structures represent the number of bonds and lone pairs of electrons of the central atom and other atoms.

Fundamentals

The formal charge is the charge carried by an atom in the molecule or ion in a particular Lewis structure. For some compounds, more than one Lewis structure can be drawn which are in resonance with each other.

Part a

The structure is as follows:

Oxygen has 6 valence electrons. It forms 3 bonds with its adjacent atoms. Hence, the number of bonding electrons is 6. One non-bonding pair of electrons is present in oxygen atom.

Calculate the formal charge of oxygen as follows:

Therefore, the formal charge on oxygen is +1.

Part b

The Lewis structure of the compound given in Part a is as follows:

Here, oxygen carries positive charge. The alternate Lewis structure of this compound is given by breaking the bond between carbon and oxygen.

The alternative Lewis structure of the compound given in Part a is as follows:

Here, carbon carries positive charge and oxygen formally neutral.

Ans: Part a

Therefore, the formal charge on oxygen atom is +1.

Part b

The alternative Lewis structure of the compound given in Part a is as follows: