How would I make the VSEPR for potassium iodide (KI) I believe I made the right Lewis Structure, but am confused on what geometry a VSEPR structure would be.
Thanks!
KI is an ionic compound. Does it have a VSEPR structure any different than a K^+ here and an I^- somewhere around it?
To determine the VSEPR (Valence Shell Electron Pair Repulsion) geometry of potassium iodide (KI), we need to follow these steps:
Step 1: Determine the Lewis structure
First, let's draw the Lewis structure for KI. Potassium (K) has 1 valence electron, while iodine (I) has 7 valence electrons. Together with the electron from the -1 charge of Iodide (I-), we have a total of 8 valence electrons.
Lewis structure for KI:
K: [ ] I: [ ] [ ] [ ] [ ] [ ] [ ]
Step 2: Calculate the total number of electron groups
Next, count the total number of electron groups around the central atom, in this case, Iodine (I). An electron group can be a lone pair or a bond. In the Lewis structure for KI, there are two electron groups.
Step 3: Determine the electron group arrangement
Next, we determine the arrangement of the electron groups based on the VSEPR theory. The possible arrangements are:
- Linear (180° bond angles)
- Trigonal planar (120° bond angles)
- Tetrahedral (109.5° bond angles)
- Trigonal bipyramidal (120° and 90° bond angles)
- Octahedral (90° bond angles)
Step 4: Determine the molecular geometry
Finally, based on the number of bonding and non-bonding electron pairs, we determine the molecular geometry.
In the case of KI, there is a bond between potassium (K) and iodine (I), as well as two lone pairs on iodine (I). So the electron group arrangement is trigonal bipyramidal. However, since both the axial and equatorial positions have lone pairs, the molecular geometry ends up being bent.
Therefore, the VSEPR geometry of potassium iodide (KI) is bent.
Note: The VSEPR model helps us predict the shape of molecules by considering the repulsion between electron groups around the central atom. This model is based on the assumption that electron pairs (whether bonding or lone pairs) repel each other and position themselves in a way to minimize the repulsion.