Question

'Name the elements present in sulphur dioxide and write each of the elements' valencies.'
Please help with the question. Will reward 15 points.

Answer 1

Explanation:

Valence of S ranges between -2 to +VI depending upon number of electrons involved in bonding.

First of all S atomic number 16 with valence shell configuration [Ne] 3s2 3p6 can accept 2 electrons from a suitable donor can become 2 - i.e.S(2-) ion as in Na2S or can share 2 electrons with more electronegative atoms exhibiting oxidation state -II as in H2S.In case of allotropes of elemental sulphur since only S atoms are covalently bonded to each another the oxidation state of every S atom is zero.

Now depending upon promotion of s & p electrons to energetically accessible low lying 3 d orbitals , the valance can be +II, +IV , +VI.

Thus S has variable valencies differing by 2 units.(unlike transition elements which may differ by 1,2,3 units).