Which Burns More? Water or Steam at 100°C

[Brammo]

Which is more likely to cause a serious burn, 100$^{o}$C of water or an equal mass of 100$^{o}$C of steam.

I was thinking that because the steam has a lower heat capacity it would do less lamage as it has a lesser ability to transfer heat. Or has it got nothing to do with heat capacity? I am a bit confused.

Or is is it to do with the thermal conductivity?

 

[cjl]

The steam would actually have a higher total heat capacity, since it could condense into 100C water and release energy in the process (and then it would still be water at 100C). I suspect the water will give a more serious burn though, due to the higher thermal conductivity. Even though the steam has more energy, the water will conduct it into the skin of the person touching it much faster.

 

[Brammo]

Brilliant thank you.

 

[olivermsun]

The question is a bit odd as posed. Equal masses of steam and water were assumed, but what's the likelihod that the same mass of steam and water would contact the victim?

 

[PJC01]

I can clarify that it is not just about the heat capacity or thermal conductivity, but also about the phase change of the substance. When water is heated to 100°C, it remains in its liquid state. However, when it reaches its boiling point, it undergoes a phase change and turns into steam. During this phase change, a significant amount of energy is absorbed by the water molecules, making steam a much more efficient carrier of heat energy.

Therefore, steam at 100°C is more likely to cause a serious burn compared to water at the same temperature. This is because steam has a higher amount of internal energy due to its phase change, and it can transfer this energy to the skin more quickly and efficiently. On the other hand, water at 100°C would need to absorb more heat energy to reach its boiling point and cause a phase change, making it less likely to cause a serious burn.

It is also worth noting that steam has a lower density compared to water, which means it can cover a larger surface area and potentially cause a more severe burn. However, the severity of the burn would also depend on the duration of contact and the individual's sensitivity to heat.

In conclusion, both water and steam at 100°C can cause serious burns, but steam is more likely to do so due to its phase change and higher internal energy. It is important to handle both substances with caution and take necessary safety measures to avoid any burns.