Complete the Lewis structure for the following molecule. This molecule has __________ sigma bonds and __________ pi bonds.
A) 11, 5
B) 13, 3
C) 4, 5
D) 13, 2
E) 6, 3

Question

Complete the Lewis structure for the following molecule.  This molecule has __________ sigma bonds and __________ pi bonds.
A) 11, 5 
B) 13, 3 
C) 4, 5 
D) 13, 2 
E) 6, 3

Quizplus · Accepted Answer

To draw the Lewis structure, we first need to determine the number of valence electrons in the molecule. We have:

- 4 carbon atoms, each with 4 valence electrons: 4 x 4 = 16 electrons 
- 2 nitrogen atoms, each with 5 valence electrons: 2 x 5 = 10 electrons 
- 10 hydrogen atoms, each with 1 valence electron: 10 x 1 = 10 electrons

Total = 36 valence electrons

Next, we need to arrange the atoms in a reasonable way. Since carbon is in the middle of the periodic table, it is reasonable to assume that it is the central atom. The two nitrogen atoms can each form a triple bond with the central carbon atom, and the carbon atoms can each form a single bond with the nitrogen atoms. The hydrogen atoms can then be added to the carbon atoms.

The Lewis structure for this molecule is:

H    H
     |    | 
H--C≡N    N≡C--H 
     |    |
     H    H

This structure has 13 sigma bonds (4 C-N, 4 C-H, and 5 N-H) and 3 pi bonds (2 in the C-N triple bonds and 1 in the N-N bond). Therefore, the answer is B: 13, 3.

Complete the Lewis Structure for the Following Molecule