The boiling point of water is far higher than that of hydrogen sulphide, although sulphur lies below oxygen in the same group, because
- A. water molecules are hydrogen bonded to one another
- B. water has a larger molar mass
- C. hydrogen sulphide is an ionic compound
- D. water molecules are non polar
Explanation
Extensive hydrogen bonding between water molecules must be overcome before they can escape, so a great deal of energy is needed and water is liquid at room temperature. Hydrogen sulphide has a larger molar mass yet boils at minus 60 degrees Celsius, which proves that molar mass is not the deciding factor. Sulphur is too large and not electronegative enough to support hydrogen bonding.