Which molecule has octahedral geometry?

Which molecule has octahedral geometry?

• A. Methane
• B. PCl5
• C. SF6
• D. H2O

Answer: (C)

Octahedral geometry comes from a central atom with six electron domains arranged around it, all of which are bonding pairs and no lone pairs to distort the shape. In sulfur hexafluoride, sulfur is bonded to six fluorine atoms and has no lone pairs on sulfur, so the six S–F bonds arrange in an octahedral pattern. The other molecules don’t have six bonding pairs around a single center: methane has four C–H bonds in a tetrahedral arrangement; water has two bonding pairs plus two lone pairs on oxygen, giving a bent shape; phosphorus pentachloride has five bonds around phosphorus in a trigonal bipyramidal arrangement.

Octahedral geometry comes from a central atom with six electron domains arranged around it, all of which are bonding pairs and no lone pairs to distort the shape. In sulfur hexafluoride, sulfur is bonded to six fluorine atoms and has no lone pairs on sulfur, so the six S–F bonds arrange in an octahedral pattern. The other molecules don’t have six bonding pairs around a single center: methane has four C–H bonds in a tetrahedral arrangement; water has two bonding pairs plus two lone pairs on oxygen, giving a bent shape; phosphorus pentachloride has five bonds around phosphorus in a trigonal bipyramidal arrangement.