Steam vs water

[Matthew Chan 1B]

Could someone explain the example that Lavelle went over with steam and why it has much more severe burns than liquid water?

[Brian J Cheng 1I]

Short answer: because steam has more phase changes than water, it releases more energy when it comes into contact with your skin. It transfers more energy to your skin resulting in greater damage.

[MAC 4G]

Here's a more detailed answer: viewtopic.php?t=1844

[Justin Quan 4I]

To clarify, when steam comes into contact with a cool surface such as your skin, it will undergo a phase change from vapor to liquid. As the steam is changing from gas to liquid, it will release all the heat absorbed that caused the phase change in the first place. If you look at the image above, the horizontal line labeled boiling is all the heat absorbed to change water from liquid to gas. If a gas returned back to the liquid state, it has to release all that heat, thus transferring more energy to your skin resulting in greater damage.

[ALegala_2I]

How does the delta H of water when it is melting compare to the delta H of water when it is vaporizing?

[Kavya Immadisetty 2B]

Steam, despite being at the same temperature as water, has more energy because during a phase change, a substance can absorb energy without increasing in temperature. This excess energy is transferred to your skin and causes burns