Comparison of Hydrides of Oxygen and Sulfur:
These hydrides have points of similarity as well as difference.
Points of Similarity:
| Property | Water, H2O | Hydrogen Sulfide, H2S |
|---|---|---|
| Nature | Water is a covalent compound but has a polar character. | Hydrogen sulfide is also a covalent compound having a polar character. |
| Structure | Water is a bent molecule having V-shape. | Hydrogen sulfide is also a bent molecule having V-shape. |
Points of Differences:
| Property | Water, H2O | Hydrogen Sulfide, H2S |
|---|---|---|
| Physical State | It is a colourless liquid at room temperature. | It is a colourless gas at room temperature. |
| Smell | It has no smell. | It has a smell like that of rotten eggs. |
| Action of Litmus Paper | It has no action on litmus paper and is neutral. | It is acidic in nature and turns blue litmus paper red. |
| Action of Alkalis | It has no action on alkalis. | It reacts with alkalis to form the sulfides. |
| Action of Metal Ions | It does not react with metal ions. | It reacts with metal ions to give coloured precipitates of metal sulfides. |
| Reducing Property | Water is not a reducing agent. | Hydrogen sulfide is a strong reducing agent. |
| Action of Lead Acetate Solution | It remains unaffected in water. | The solution turns black. |
Water is a liquid at room temperature while hydrogen sulfide is a gas at room temperature. The reason is that water molecules are associated with hydrogen bonding. The high electronegativity of oxygen and its small size makes the water more polar than hydrogen sulfide. This results in a close approach of water molecules through hydrogen bonding.
