Question

draw the best lewis structure for SF₄²- and calculate the formal charge on sulfur

 Draw the best Lewis structure for CH₆N⁺ and calculate the formal charge on nitrogen.

Answer 1

Sol :-

Number of valence electrons in S = 6

Number of valence electrons in F = 4 x 7 = 28

and

Number of electrons added = 2

So,

Total number of valence electrons in SF₄^2- = 6 + 28 + 2 = 36 electrons

Now,

As, Formal charge on atom = No. of valence electrons in S - No. of shared electrons/2 - No. of unshared electrons

= 6 - 8/2 - 4

= 6 - 4 - 4

= 6 - 8

= -2

Hence, formal charge on S = -2

and

Lewis structure of SF₄^2- is :