Question

Why does water show a higher boiling point as compared to hydrogen sulphide \[?\] Give reasons for your answer.

Answer 1

Hint: The boiling point of a substance is the temperature at which the vapor pressure of a liquid equals the pressure surrounding the liquid and the liquid changes into gas/vapor.
To show water has the highest boiling point as compared to hydrogen sulphide. First, we have to know the boiling points show the strength of forces between molecules. The more they stick together, the more energy it will require to transform liquid state into vapours.

Complete answer:
The boiling point of water is \[{100^o}C\] under normal atmospheric pressure. Also, the boiling point of hydrogen sulphide \[ - {60^o}C\].

Water shows higher boiling point as compared to hydrogen sulphide due to the presence of hydrogen bonding between \[O\] and \[H\] in water molecules due to high electronegativity and small size of oxygen atom. To break these \[H - \] bonds, a large amount of energy is needed and hence the boiling point of \[{H_2}O\] is high.
On the other hand, sulphur being less electronegative \[\left( {E.N. = 2.5} \right)\], hydrogen bonding does not occur in hydrogen sulphide and also \[{H_2}S\] is a gas at room temperature, hence molecules are free as compared to \[{H_2}O\].

Note:
Note that the matter at solid state has the highest boiling points because the most amount of energy is required to break the bonds between the atoms in solids. Liquid helium has the lowest boiling point of almost all liquids. Boiling points increase as the number of carbons is increased.