Question

Explain giving reason the following:

SF₆ is known but SH₆ is not known.

Answer 1

1. SF₆ is known because sulphur can expand its octet using available vacant d-orbitals, allowing six fluorine atoms to bond.
2. SH₆ is not known because hydrogen cannot expand its octet; it can form only one bond.
3. Also, sulphur forms strong S-F bonds leading to a stable SF₆, whereas S-H bonding in SH₆ would be unstable and not favoured.
4. Hence, the inability of hydrogen to accommodate more than one bond and expand its valence shell is the main reason SH₆ is not known.