Question

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

Short answer

A burn from steam is typically more severe than a burn from boiling water because steam carries more heat energy due to the absorbed latent heat during the phase change from water to steam. When steam comes into contact with our skin, it condenses back into water and releases this additional latent heat, transferring more heat energy to our skin than boiling water at the same temperature, resulting in a more severe burn.

Step-by-step solution

Consider the temperatures

Boiling water and steam both typically have the same temperature, around 100°C (212°F) at standard atmospheric pressure. However, if the steam is above boiling temperature (called superheated steam), it could cause more severe burns due to its higher temperature.

Understand heat transfer

When our skin comes into contact with boiling water or steam, a heat transfer occurs. Heat transfers from the hot substance (steam or boiling water) to our cooler skin. The greater the difference in temperature, the faster the heat transfer occurs and the more severe the burn.

Consider the energy involved

The crucial difference between boiling water and steam is the amount of energy they carry. When water turns into steam, it absorbs a large amount of energy called latent heat. This is the energy required for a substance to change its phase from liquid to gas without a change in temperature. As a result, steam carries significantly more heat energy compared to boiling water at the same temperature.

Steam releases additional energy upon contact

When steam at 100°C comes into contact with our skin, it condenses back into water while releasing the additional latent heat. This release of latent heat causes a larger amount of heat energy to be transferred to our skin compared to a burn from boiling water, resulting in a more severe burn. In conclusion, a burn from steam is typically more severe than a burn from boiling water due to the additional latent heat released when steam condenses back into water, transferring more heat energy to our skin than boiling water would at the same temperature.