Question

Why is a burn from steam typically much more severe than a burn from boiling water?

Short answer

The reason is the latent heat of vaporization.

Step-by-step solution

Latent heat of vaporization

The latent heat of vaporization is the amount of heat energy required to convert one gram of a liquid into its vapor.

The latent heat of vaporization of water at $100°C$is $40.6 kJ/mol$.

Steam is already in its vapor state, so it is not required to provide this extra energy to convert it into steam, just like water.

 Step 2: Explanation

This is because when water is transformed into steam at 100° C, it absorbs the latent heat of vaporization.As a result, steam has more heat at the same temperature than water. Thus steam emits far more heat to the skin than boiling water, resulting in more severe burns.