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# VSEPR for 5 electron clouds (part 2)

In this video, we continue exploring VSEPR theory for molecules and ions with five regions or “clouds” of electrons around the central atom, focusing on examples where the molecular geometry is T-shaped (two of the clouds are lone pairs) or linear (three of the clouds are lone pairs). Created by Jay.

## Want to join the conversation?

• For CIF3 my intuition tells me that putting the 2 lone pairs on the north and the south balances the bond more. The 3 Fluorine will be on the equatorial positions with 120 degree angle from each other. I do understand that by putting the lone pairs on the north and south will have a 90 degree angle, which will be closer to affect the Fluorine atoms, which are located on the equatorial position. However, because we have two lone pairs on the opposite sides of each other, it will have the same amount of push to all the Fluorine atoms. Thus will create an equilibrium to the atom by making it more balance. Is the way I am thinking correct? or am I very wrong. Thank you for your help in advance.
• I totally get what you are saying, and it totally makes sense in terms of balancing each other out. However, one of the tenets of VSEPR theory is that lone pairs oriented themselves as far apart as possible from other lone pairs as well as bonding pairs to minimize their interactions since they are all negatively charged.

When the electron pairs are in the axial positions (north and south), they are always only 90 degrees from every bond. However, when the electron pairs are in the trigonal positions, then they are 120 degrees from each other and 90 degrees from the axial bonds. That means in the latter they are oriented as far apart as possible.
• Why cant we put double bonds on each side of the centeral atom and leave on lone pair of electron the formal charge will be +1 ?
• If you had two double bonds the the central Iodine, the Formal Charge on the outside Iodines would each be +1. Since there are two that would induce a net force of +2 on the molecule. The way Sal draws it leaves a Formal Charge of -1 on the Internal Iodine with a 0 on the outside Iodines. Net force on this molecule then is -1. This is the preferred resonance structure
• In these VSEPR videos, Jay keeps saying "its ok for X element to break the octet rule because its on the 3rd period". I understand why this is ok when the formal charge equals out to be 0. I don't understand why the 3rd period allows this.
• The general explanation is that elements in the third period and on have empty d orbitals they can use to bond.
• I tend to get confused with the term equatorial. Is their an easy way you can explain to me what that means? So I can grasp a better picture. Thanks!
• equatorial is like the equator - a horizontal line either pointing slightly upwards or downwards. often this is confused with axial which refers to straight up and down.
• And why is it I3-? not I3?
• The structure will look like: I-I-I
So, each the two iodines on the side have a single bond and the one in the center has two single bonds. The two iodines on the sides have neutral charge because they have 8 electrons but the one in the center now has more electrons than needed (9) which is why it is negatively charged. It is made from I2 + I(-) --> I3(-)
• why dont we take lone pair above and below the Cl atom
• The lone pairs are nonbonding, so they occupy more space than the bonding pairs.
If they occupy the axial positions, the three bonding pairs are at angles of 90° to the lone pairs, and there is a certain LP-BP repulsion,
In the equatorial positions, the angles are 120°. Since the repulsions decrease with the square of the distance, the equatorial positions are preferred.
lone pairs will always occupy the equatorial locations if possible.
• why do we ignore lone pair electrons for final structure in vsepr theory?
• Because that's how molecular geometry is defined, it's only based on the shape of the bonded atoms.
• At why can't you put the lone electron clouds on the axial positions? Wouldn't that minimize electron repulsion?