why the shape of the molecules of SF6 and BrF5 different even though their hybridisation is of the type sp3d2 ? Explain.
why the shape of the molecules of SF6 and BrF5 different even though their hybridisation is of the type sp3d2 ? Explain.
Even though both SF6 and BrF5 have the same hydridisation, yet the shape of the two molecules is different because in SF6, all the six valence electrons are used for bonding. The electronic configuration of S is [Ar]3s23p4. Therefore all the 6 electrons present in the third shell are used for bonding and there is / are no lone pair of electrons in valence shell of SF6. Hence the structure of SF6 is a perfect octahedron with no lone pair of electrons. All the six positions are occupied by bond pairs.
On the other hand, in BrF5, there are 5 bond pairs and a lone pair of electron. The electronic configuration of Br is [Ar]3s23p5. Here, out of 7, 5 valence electrons are used in bonding. The remaining two electrons constitute a lone pair. Therefore BrF5 has an octahedral structure in which one of the positions is occupied by a lone pair of electrons. Hence its shape is square pyramidal.
Thus SF6 is a perfect octahedron while BrF5 is square pyramidal in shape.
Even though both SF6 and BrF5 have the same hydridisation, yet the shape of the two molecules is different because in SF6, all the six valence electrons are used for bonding. The electronic configuration of S is [Ar]3s23p4. Therefore all the 6 electrons present in the third shell are used for bonding and there is / are no lone pair of electrons in valence shell of SF6. Hence the structure of SF6 is a perfect octahedron with no lone pair of electrons. All the six positions are occupied by bond pairs.
On the other hand, in BrF5, there are 5 bond pairs and a lone pair of electron. The electronic configuration of Br is [Ar]3s23p5. Here, out of 7, 5 valence electrons are used in bonding. The remaining two electrons constitute a lone pair. Therefore BrF5 has an octahedral structure in which one of the positions is occupied by a lone pair of electrons. Hence its shape is square pyramidal.
Thus SF6 is a perfect octahedron while BrF5 is square pyramidal in shape.
