Question

What produces more severe burns, boiling water or steam?

Answer 1

The two different states of matter, have different energies within it at the same temperature. The change of state from one form to another takes place through the gain or release of energy known as the latent heat of vaporisation. So, the one with higher energy will cause more burn.

Complete step by step answer:
Firstly, both the water and the steam are the two states of water molecules, that is liquid and gaseous state respectively. But, in the two states of ${{H}_{2}}O$ molecule, the amount of energy present at a particular temperature is not equal, as energy is provided to change the state of matter from one form to another. The state change from water to steam, takes place when more heat is provided to the one mole of water above its boiling point temperature of ${{100}^{\circ }}C$, under standard atmospheric conditions, the liquid state changes to the gaseous form. This extra heat provided is stored in the gaseous form known as the Latent heat of vaporisation.
So, at the same temperature, the steam has more energy compared to the boiling water. When the steam comes in contact with the skin, it undergoes the change of state through condensation, along with the release of the latent heat within it. Thus, causing more severe burn than the boiling water.

Note: The latent heat of vaporisation is related to the physical property of the substance, that is, its heat energy. It is expressed in Joules/kg or Joules/mole. The latent heat of vaporisation of water is 2260 J/kg or 40.8 J/mol. It is related to the enthalpy, as latent heat is the difference of the heat energy or enthalpy of two different states at same temperature.