VSEPR predicts an SbF5 molecule will be which of the following shapes?
Question 11 options:
a) tetrahedral
b) trigonal bipyramidal
c) square pyramid
d) trigonal planar
e) square planar
b) trigonal bipyramidal
To determine the shape of a molecule using VSEPR theory (Valence Shell Electron Pair Repulsion theory), follow these steps:
1. Identify the central atom: In this case, the central atom is antimony (Sb).
2. Determine the number of electron groups around the central atom: To do this, count the number of bonding groups (atoms directly bonded to the central atom) and lone pairs (electron pairs not involved in bonding) around the central atom. In the case of SbF5, there is 1 bonding group (F) and 5 lone pairs (F lone pairs).
3. Use the VSEPR chart: Based on the number of electron groups, refer to the VSEPR chart to determine the molecular geometry associated with that number. Here is a summary:
- 2 electron groups: linear
- 3 electron groups: trigonal planar
- 4 electron groups: tetrahedral
- 5 electron groups: trigonal bipyramidal
- 6 electron groups: octahedral
4. Determine the shape: The molecular shape will be determined based on the arrangement of the electron groups, considering both bonding groups and lone pairs.
In the case of SbF5, there is 1 bonding group (F) and 5 lone pairs (F lone pairs), which gives a total of 6 electron groups. According to the VSEPR chart, 6 electron groups correspond to an octahedral shape.
Therefore, the correct answer is not listed in the given options. The shape of an SbF5 molecule is octahedral, which consists of six bonding groups/lone pairs arranged around the central atom in a symmetrical manner.
In order to determine the shape of the SbF5 molecule, we need to apply the principles of the VSEPR (Valence Shell Electron Pair Repulsion) theory. VSEPR theory states that the shape of a molecule is determined by the repulsion between electron pairs in the valence shell of the central atom.
In the case of SbF5, antimony (Sb) is the central atom and there are five fluorine (F) atoms attached to it. The electron configuration of antimony is [Kr]5s24d105p3, and each fluorine atom brings 1 electron to form Sb-F bonds.
Therefore, the steric number (the sum of the number of bonded atoms and lone pairs around the central atom) of antimony in SbF5 is 5.
Based on this steric number, we can determine the shape of the molecule. A steric number of 5 corresponds to the trigonal bipyramidal geometry. This means that the SbF5 molecule will have a trigonal bipyramidal shape.
Hence, the correct answer is b) trigonal bipyramidal.