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# Lone Pairs Help! watch

1. Hey people, so I was reading about shapes of molecules and looked at CO2 and it doesn't have 4 lone pairs of electrons, which is weird because I thought that it would have 4 lone pairs on the oxygens as each oxygen atom has 6 electrons and the carbon atom has 4 electrons, so the 2 double bonds would mean all 4 electrons of carbon would be bonded and 4 electrons for oxygens, so what about the other 8? I'm so confused

Any help would be appreciated
2. It's shape is:

O=C=O

The carbon has two double bonded oxygens to each side, giving a bond angle of 180 degrees, because there are 2 atoms and no lone pairs on the carbon. Each oxygen atom has 2 lone pairs, meaning that each atom has 8 electrons, making the compound chemically stable.
3. (Original post by thegodofgod)
It's shape is:

O=C=O

The carbon has two double bonded oxygens to each side, giving a bond angle of 180 degrees, because there are 2 atoms and no lone pairs on the carbon. Each oxygen atom has 2 lone pairs, meaning that each atom has 8 electrons, making the compound chemically stable.
So does the angle only alter when the central atom has a lone pair of electrons?
4. (Original post by Nator)
So does the angle only alter when the central atom has a lone pair of electrons?
Yes, e.g. water.

The oxygen also has 2 atoms bonded to it (as does the carbon in CO2), but instead it has 2 lone pairs of electrons, which the carbon in CO2 doesn't. This means that the bond angle between the O and H atoms is approximately 104.5 degrees.
5. (Original post by thegodofgod)
Yes, e.g. water.

The oxygen also has 2 atoms bonded to it (as does the carbon in CO2), but instead it has 2 lone pairs of electrons, which the carbon in CO2 doesn't. This means that the bond angle between the O and H atoms is approximately 104.5 degrees.
Right, but what if there was a lone pair on an atom which wasn't the central one, and the rest had no lone pairs, does it happen and if so, would the bond angle be affected?
6. (Original post by Nator)
Right, but what if there was a lone pair on an atom which wasn't the central one, and the rest had no lone pairs, does it happen and if so, would the bond angle be affected?
If, for example in H2O, one of the hydrogen atoms had a lone pair, this would not affect the shape of the molecule. It's only when there is a lone pair of electrons on the central atom (the atom to which other atoms are bonded), there is a change in the bond angle - the greater the number of lone pairs, the smaller the bond angle due to lone pair - lone pair repulsion.

Have a look at the Valence Shell Electron Pair Repulsion Theory (VSEPR Theory):

VESPR Theory

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