I want to know why the steam is hotter than the hot water?
At 1 atmosphere of pressure, water is liquid between 0 C and 100 C. At 100 C, it is converted to steam (vapor) by absorbing the
latent heat of vaporization. At 100 C, both vapor and liquid co-exist. Above 100 C, it is only steam.
If you were to expose something cold to steam, the steam would cool to 100 C and give up to the cold body, the specific heat of steam. Once it reached 100 C, it would condense and give up to the cold body the specific heat of vaporization (enthalpy of vaporization).
Specific heat capacity, ice: 2.108 kJ/kg-K
Specific heat capacity, water: 4.187 kJ/kg-K
Specific heat capacity, water vapor: 1.996 kJ/-kgK
Enthalpy of vaporization (liquid-vapor) 2257 kJ/kg
There are two things to note. First, the specific heat of water is more than double that of steam. That's because of the hydrogen bonds that are broken when water vaporizes. Second, note how much higher the enthalpy of vaporization is than any of the specific heats. There is a lot of energy in steam! This is the main reason why people say that steam is much hotter than hot water. Steam and water may be at or nearly at the same temperature, but there's a lot of energy in the steam that is not in the water.