Carbide (C22-) Lewis Structure
Carbide (C22-) ion contains only two carbon atoms. Each carbon atoms have -1 charge and there is a triple bond between carbon atoms. Also there is a lone pair on each carbon atom in C22- lewis structure.
C22- lewis structure
Several characteristics of C22- lewis structure are mentioned below.
- There is a triple bond between carbon atoms.
- Each carbon atom has a lone pair and -1 charge.
Steps of drawing lewis structure of C22-
When we draw a lewis structure, there are several guidelines to follow. Number of steps can be changed according the complexity of the molecule or ion. However those all steps are mentioned and explained in detail in this tutorial to improve your knowledge about lewis structure drawing.
- Find total number of electrons of the valance shells of carbon atoms.
- Determine total electrons pairs existing as lone pairs and bonds
- Deciding center atom selection
- Mark lone pairs on atoms
- Mark charges on atoms if there are charges.
- Check the stability and minimize charges on atoms by converting lone pairs to bonds to obtain best lewis structure.
Total number of electrons of the valance shells of CH3CH2OH
There is only one element in carbide ion; carbon. Carbon is a group IVA element in the periodic table and has four electrons in its last shell (valence shell).
- valence electrons given by carbon atoms = 4 * 2 = 8
Because, there is a -2 charge in carbide ion, two electrons should be added to total number of valence electrons.
- valence electrons given due to -2 charge = 2
- Total valence electrons = 8 + 2 = 10
Total valence electrons pairs
Total valance electrons pairs = σ bonds + π bonds + lone pairs at valence shells
Total electron pairs are determined by dividing the number total valence electrons by two. For, carbide ion, total pairs of electrons are five (=10/2) in their valence shells.
Center atom of carbide ion
because there is only two carbon atoms, no need to find center atom. Basic skeletal structure of carbide ion is given below.
Lone pairs on atoms
After determining the center atom (did not need to do this for carbide ion) and skeletal of carbide ion, we can start to mark lone pairs on atoms. Remember that, there are total of five electron pairs.
- There is only one bond in the drawn skeletal. So, now only four electron pairs are remaining to mark as lone pairs.
- Usually, those two remaining electron pairs should be started to mark on outside atoms.
- But, in this example, we do not have outside atoms because there is no defined center atom. Therefore, we can mark those remaining electrons pairs on carbon atoms.
- Then, one carbon atom will take three lone pairs and other carbon atom will take one lone pair as following figure.
Mark charges on atoms in ethanol
There are charges on carbon atoms in above structure.
Check the stability and minimize charges on atoms by converting lone pairs to bonds
Because three are charges on both carbon atoms and having charges like -3 reduces the stability of molecule or ion. Therefore we need to do the step of reducing charges on atoms by converting lone pairs to bonds. Also. one carbon atom do not have eight electrons in its valence shell. Therefore , that structure is not stable whatsoever.
Now, we are going to convert one lone pair to a bond as following.
In the new structure too, there is -2 charge on one carbon atom and other carbon atom has not gained eight electrons in its valence shell.
Because distributing charges all over the molecule or ion will stable the molecule or ion, we can convert one more lone pair on carbon atom as below.
Questions
In carbide ion, there are 2- charges. How these 2- charge is located on carbon atoms?
There are only two carbon atoms in carbide ion. Each carbon atom has -1 charge. Because, there are two carbon atoms, overall charge is -1*2 = -2
Because, each carbon atom has -1 charge, should oxidation number of a carbon atom be -1 too?
In carbide ion, oxidation of each carbon atom is -1. But, there is no rule to be have a same oxidation number and charge for an atom in a compound.
What is carbide ion charge?
Charge of carbide ion is -2.
