Question

h2o is a liquid whereas h2s is gas at room temperature?why

Answer 1

In H2O there is hydrogen bonding between the molecules because oxygen has a high electronegativity(only second to flourine).

So, the hydrogen atoms from a water molecule forms hydrogen bonding with oxygen of neighbouring water molecule resulting in strong intermolecular hydrogen bonding. This is why water is in liquid form at room temperature

While in case of H2S, the electronegativity of sulphur is low compared to oxygen so,the hydrogen bonding is negligible in case of H2S, and the only binding force is weak Van Der Wals or London force of attraction between the molecules. Therefore H2S is a gas at room temperature.

Answer 2

Answer:

Oxygen has smaller size and higher electronegativity as compared to sulphur. Therefore, there is extensive hydrogen bonding in H2O, which is absent in H2S. Molecules of H2S are held together only by weak van der Waal's forces of attraction. Hence, H2O exists as a liquid while H2S as a gas.