Why Hydride of sulphur is reducing agent , whereas Hydride of oxygen is not ?
Why Hydride of sulphur is reducing agent , whereas Hydride of oxygen is not ?
The reducing character of hydrides depends on thermal stability as higher the thermal stability lower will be the reducing character.
Due to smaller size and higher electronegativity in oxygen, it has internal hydrogen bonding in hydrides (i.e. H2O) while in case of Sulphur, the presence of d-orbital increases the size and co valency limit and so it does not have internal H-bonding in H2S.
Hence, the additional H-bonding makes the water molecule very stable in comparison with the H2S molecule which has larger bond due to larger size of S-atom and thus it becomes weaker.
In this way, the hydride of oxygen (H2O) becomes thermally more stable than H2S. So it does not behave as reducing agent while H2S behaves as reducing agent.
The reducing character of hydrides depends on thermal stability as higher the thermal stability lower will be the reducing character.
Due to smaller size and higher electronegativity in oxygen, it has internal hydrogen bonding in hydrides (i.e. H2O) while in case of Sulphur, the presence of d-orbital increases the size and co valency limit and so it does not have internal H-bonding in H2S.
Hence, the additional H-bonding makes the water molecule very stable in comparison with the H2S molecule which has larger bond due to larger size of S-atom and thus it becomes weaker.
In this way, the hydride of oxygen (H2O) becomes thermally more stable than H2S. So it does not behave as reducing agent while H2S behaves as reducing agent.
