Calculate the formal charge on each non-hydrogen atom in eachof the following molecules (show your work)
i know the answer but can someone tell me how to get to the answer?
1) H2C=N=N(2 dots on top and on side)
2. H2C-N(3 bonds)C(2dots)
Draw the Lewis structure. Apparently you have that. I must not have read your description correctly for I think you should have 18 electrons and I count only 16 from your post.
You should have, for a neutral molecule,
H = 1e
H = 1e
C = 6e
N = 5e
N = 5e
total e = 18.
I count 2 for CH bond.
2 for the other CH bond.
4 for left double bond on N.
4 for right double bond on N.
4 long pairs (2 on top and 2 on side of rightmost N).
Total 16 used. Where are the other two? or does the molecule have a -2 charge?
How to draw a lewis Dot structure for LiCl
To calculate formal charges on atoms in a molecule, you need to follow these steps:
1) Determine the Lewis structure: Start by drawing the Lewis structure of the molecule, which shows the arrangement of atoms, their bonds, and lone pair electrons.
2) Assign electrons: Distribute all the valence electrons around the atoms according to the octet rule. Hydrogen usually forms only one bond, and elements from the second period onwards (except for boron) tend to form bonds with eight electrons around them.
3) Calculate formal charge: Formal charge (FC) is calculated using the formula: FC = valence electrons - (lone pair electrons + 1/2 bonding electrons). Valence electrons are the group number of the element in the periodic table.
Let's apply these steps to the provided molecules:
1) H2C=N=N (2 dots on top and on the side):
- Draw the Lewis structure, considering that carbon (C) is the central atom:
H:C=N:::N-H
- Assign electrons: Carbon has four valence electrons and forms four bonds. The nitrogen (N) atoms each have five valence electrons and form three bonds.
- Calculate formal charge:
- Carbon (C): FC = 4 - (0 + 4/2) = 0
- Nitrogen (N) (atoms with two dots):
- The left nitrogen (N) has a single bond (2 electrons in the bond) and two lone pairs (4 electrons in total) on the top and side. FC = 5 - (4 + 2/2) = 0.
- The right nitrogen (N) has a double bond (4 electrons in the bond) with one lone pair (2 electrons). FC = 5 - (2 + 4/2) = -1.
2) H2C-N(3 bonds)-C(2 dots):
- Draw the Lewis structure:
H:C-N-C(:)
- Assign electrons: Carbon has four valence electrons and forms four bonds. Nitrogen has five valence electrons and forms three bonds. Hydrogen usually has one bond.
- Calculate formal charge:
- Carbon (C): FC = 4 - (0 + 4/2) = 0
- Nitrogen (N): FC = 5 - (0 + 3/2) = +1
Remember, the formal charge provides information about the distribution and stability of electrons around each atom in a molecule. It helps determine the most plausible Lewis structure.