H2S is a gas and and water is liquid at room temperature. Because, In water there is strong hydrogen bonding, and the molecules get extensively associated by weak electrostatic forces. So, water exists as a liquid at room temperature with a high boiling point. Whereas, Sulphur is less electronegative than oxygen, and the S-H bond is much less polar than the O-H bond. Hence, there is no hydrogen bonding in hydrogen sulphide, and it exists as a gas.