H2O is a liquid but H2S is a gas why?
Due to the high electronegativity of oxygen, the intermolecular H-bonding in H2O occurs producing the associated molecule of much higher molecular weight. Therefore, bipolar which is dependent on molecular weight also increases.
As sulphur is much less electronegative than oxygen, no H-bonding formation takes place in H2S and H2S molecules don’t associate through H-bonding. Hence, water is liquid but H2S is a gas at ordinary temperature.