how do u draw the lewis structure for something like CO -2 over 3. do u add 2 electrons on to the oxygen when yur finding the number of valence electrons cuz that's wat i thought u did but then i got all those questions wrong so wat do u do
It's very difficult to draw structures on these boards. I'll try to draw and talk you though it for the carbonate ion, CO3=. Yes, you do add two electrons to account for the negative 2 charge on the ion.
1 C with 4 electrons each = 4 e
3 O with 6 electrons each = 18 e
2 electrons for the -2 charge = 2 e
Total number of electrons = 24.
There are four atoms, each wants eight for the octet; and 4 x 8 = 32 electrons. Therefore, we need to make 24 electrons appear to be 32. There are 32 - 24 = 8 and two electrons/bond = 4 bonds. So I start with 4 bonds on C which makes a bond to each O and a double bond to one of the O atoms.
O
|
C=O
|
O
On the top O place pairs of electrons left side, top and right side. On the bottom O place pairs of electrons left side, bottom, and right side. On the side O, place pairs of electrons on top, and bottom (none on the right side). Each dash I drew stands for 2 electrons and you may replace each dash with a pair of electrons. If you have followed my instructions, there should be 8 electrons around the top O, 8 around C, 8 around the bottom O and 8 around the right O. But you should be able to count only 24 electrons. I hope this helps.
To draw the Lewis structure for CO2-3, you need to consider the total number of valence electrons and the octet rule.
1. Start by determining the total number of valence electrons:
- Carbon (C) contributes 4 valence electrons.
- Oxygen (O) contributes 6 valence electrons each. Since there are three oxygen atoms, the total number of valence electrons from oxygen is 6 x 3 = 18.
- Since the molecule has a negative charge of -2, you need to add two additional electrons.
- Add the valence electrons from all the atoms and the additional electrons: 4 (C) + 18 (O) + 2 (additional) = 24 valence electrons.
2. Now, arrange the atoms in the Lewis structure. Place the central atom, carbon (C), in the middle and the oxygen atoms (O) around it.
3. Connect the atoms using a single bond. Each bond consists of two electrons. Start by connecting carbon with one of the oxygen atoms using a single bond. This uses up 2 electrons.
4. Distribute the remaining electrons around the atoms. Since you have 22 more electrons to assign, each oxygen atom should have one lone pair, with 6 electrons each, and carbon should have two lone pairs, with 8 electrons.
5. Check if all atoms have achieved an octet of electrons (except hydrogen, which only needs two electrons). If any atoms are deficient, try to form double or triple bonds to achieve an octet.
In this case, carbon has only 8 electrons, while oxygen has more than eight. To achieve an octet for carbon, you can form a double bond between carbon and one of the oxygen atoms, using two more electrons.
The final Lewis structure for CO2-3 will have one carbon atom with a double bond to one oxygen atom, and two oxygen atoms with lone pairs.