Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

How solids in water can burn

  1. Jan 4, 2017 #1
    I was cooking oats in water yesterday and the oats at the bottom of the pot got scorched. How is this possible? Doesn't the water smother the oats from oxygen?
     
  2. jcsd
  3. Jan 4, 2017 #2

    Borek

    User Avatar

    Staff: Mentor

    You don't need oxygen for the thermal decomposition of the organic substances.

    In other words: nothing was burnt.
     
  4. Jan 4, 2017 #3
    But doesn't a combustion reaction proceed?
     
  5. Jan 4, 2017 #4

    Bystander

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

  6. Jan 4, 2017 #5

    Borek

    User Avatar

    Staff: Mentor

    No.
     
  7. Jan 4, 2017 #6
    Alright. So thermal decomposition can produce the same burnt smell and charred look that burning can?
     
  8. Jan 4, 2017 #7

    Borek

    User Avatar

    Staff: Mentor

    Yes. Charring is part of the burning - heat decomposes organic matter even before it starts to react with the oxygen.
     
  9. Jan 4, 2017 #8

    Ygggdrasil

    User Avatar
    Science Advisor

  10. Jan 5, 2017 #9
    Thanks!
     
  11. Jan 5, 2017 #10
    There are some substances that can actually "burn" under water because they are more powerful reducing agents than hydrogen and can therefore take the bound oxygen from water molecules. Magnesium metal is one example of this.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted