How many bonding pairs and lone pairs of electrons surround the sulfur atom in the \({\text{S}}{{\text{F}}_{\text{4}}}\) molecule?

A

One respondent stated that the structure of \({\text{S}}{{\text{F}}_{\text{4}}}\) is not specified in the teachers note corresponding to AS 14.1.1. This is a comment that has been made at length in previous subject reports. The AS states that candidates should be able to determine the shape and bond angles of species with five or six negative charge centres using VSEPR Theory. In the teaching programme, examples such as \({\text{PC}}{{\text{l}}_{\text{5}}}\), \({\text{S}}{{\text{F}}_{\text{6}}}\), \({\text{Xe}}{{\text{F}}_{\text{4}}}\) and \({\text{PF}}_6^ - \) should be definitely included. However, any species with five or six negative charge centres could be asked in a question and hence examples are not restricted to these latter four examples.