Two Lewis structures are given below for nitrosyl chloride (ClNO). Calculate the formal change on each atom below. Based on the formal charges, which Lewis structure gives the best representation of this molecule, i.e. which one is the dominant structure. Explain your reasoning.

Lewis structure of a molecule or ion shows electron dots symbols for the atoms, the bonding pairs as lines and lone pairs that fill valence shell of each atoms as pair dots.

Lewis structure of a molecule can be drawn based on the following rules.

i. Place the atoms relative to each other

ii. Determine the total number of valence electrons

iii. Draw a single bond from each surrounding atom to central atom and subtract two electrons from the total for each bond to find the number of electrons remaining

Distributing the remaining electrons in pairs so that each atoms ends up with eight electrons is known as Octet

Formal charge on the atoms can be calculated by using the following formula

FC= (number of valence electron) – (lone pair electron) – (½ x bonding pair electron)

To calculate the formal charge for first and second lewis structure of nitrosyl chloride; the attachment below explains the calculation in conjunction with with the above formula.

Conclusion: The formal charges from the first calculation gave the value 0 all through i.e there are no formal charges present, that makes it the dominant structure we seek but the second calculation gave a varying formal charges, that makes the structure unsuitable.

The best and the dominant structure for writing nitrosyl chloride is the one with no formal charges