Why steam burns are worse explained

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Beza Ayalew 1I
Posts: 58
Joined: Fri Sep 29, 2017 7:07 am

Why steam burns are worse explained

Postby Beza Ayalew 1I » Thu Jan 11, 2018 12:24 am

Hey, could someone please clarify why steam burns are worse than others? I know part of the explanation is that it takes around 40kJ to break liquid water bonds into water vapor, so is the reasoning just that the steam is holding in all that excess energy which causes more severe burns or not?

Kyle Sheu 1C
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Joined: Fri Jun 23, 2017 11:39 am

Re: Why steam burns are worse explained

Postby Kyle Sheu 1C » Thu Jan 11, 2018 1:59 am

In essence, yes.

When the steam hits your skin, there is a temperature difference, and heat passes from the steam to your skin as the water vapor condenses. Because there is so much more energy in steam than 100 degree water b/c of the energy "invested" during the phase change, the burn is more severe.

Sue Xu 2K
Posts: 58
Joined: Fri Sep 29, 2017 7:06 am

Re: Why steam burns are worse explained

Postby Sue Xu 2K » Thu Jan 11, 2018 11:29 am

The steam and water all tend to cool down when it get exposed to a cooler surface like the skin. But it releases extra energy to convert steam to water first, and then the extra energy, or extra heat would burns the skin worse.

Harrison Wang 1H
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Joined: Fri Sep 29, 2017 7:07 am

Re: Why steam burns are worse explained

Postby Harrison Wang 1H » Thu Jan 11, 2018 11:34 am

When steam hits your hand, it first condenses, and because ∆H for the vaporization of water is extremely high, a lot of heat is released upon contact with your body. When water hits your hand, it does not require this phase change, and the heat transferred to your body is therefore much less.

Erica Nagase 1H
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Joined: Sat Jul 22, 2017 3:00 am

Re: Why steam burns are worse explained

Postby Erica Nagase 1H » Thu Jan 11, 2018 1:08 pm

After 100 degrees, vaporization is complete so the temperature of steam can be much greater than 100 deg (think of the phase change diagram from lecture). Because the temperature is higher, there is a greater change in enthalpy.

Beza Ayalew 1I
Posts: 58
Joined: Fri Sep 29, 2017 7:07 am

Re: Why steam burns are worse explained

Postby Beza Ayalew 1I » Wed Jan 17, 2018 12:53 am

ok thanks guys, so what I got from that was the major concept is that because steam requires a phase change when in contact with the skin but liquid water doesn't, the energy needed to complete the phase change results in more burns.


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