What is the difference between an exothermic and an endothermic reaction?

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   Vellurposted 11 years ago

   What is the difference between an exothermic and an endothermic reaction?

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   annajazzposted 11 years ago

   Simply put:
   An endothermic reaction takes in energy from its surrounds. Which is why some reactions get very cold. An example of this is dissolving ammonium chloride in water.
   
   An exothermic reaction lets out energy. Often times in the form of heat. This can be seen in any type of combustion reaction.

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      Vellurposted 11 years agoin reply to this

      Thank you for answering. I get it.

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      inspposted 11 years agoin reply to this

      I agree

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3. 58

   inspposted 11 years ago

   Exothermic Reaction: Reaction that are mostly chemical and the substances that react and form a new substance cannot be gained after reversing the conditions.
   Endothermic Reaction: Reaction that is mostly physical and the substances that react and form a new substance can be gained after reversing the conditions.

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      Vellurposted 11 years agoin reply to this

      That's one important point. Thank you for replying.

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   lone77starposted 11 years ago

   @annajazz pretty well nails it.
   
   I might just add that one extremely exothermic reaction is used in building demolition -- thermite or thermate.
   
   Thermite is an incendiary made of iron oxide and aluminum. Basically, it's ordinary aluminum and iron rust. Aluminum is hungrier than iron for the oxygen. Because of that increased hunger, the aluminum steals the oxygen, and excess energy is released as a result.
   
   Fe2O3 + 2Al -> 2Fe + Al2O3 + extreme heat
   
   This heat is sufficient to melt steel. Thermate is thermite with additives to make it burn hotter and faster. Nano-thermite is a very finely powdered form where the aluminum is bonded to the iron oxide for the most explosive reaction.
   
   An example of this is the nano-thermite found in the 9/11 dust near the three (3) demolished World Trade Center buildings. Some of this material was unreacted, while some was partially reacted with tiny globules of iron attached. But throughout the 9/11 dust were an estimated several tons of iron microspheres from fully-reacted thermite. These alone prove controlled demolition. And controlled demolition proves that 9/11 was an inside job.
   
   It has been proven that this substance is at least part of what brought down all 3 of the World Trade Center buildings -- not the 2 airplanes.
   
   The rather awkward question is raised: because it takes weeks or months to prepare 3 buildings for such a controlled demolition, who all knew about it? With tenants in WTC7 like the CIA, IRS, SEC and other government agencies, one has to wonder if certain individuals within the government might have been informed in advance. In fact, certain individuals were luckily not in their offices when the planes hit those offices (in the impact zones). And could the Bush family-run security company which oversaw the World Trade Center have also been involved?
   
   Such information as this may metaphorically be called "socially exothermic," because of its explosive nature.
   
   For more information, check out the website of thousands of scientists, engineers and architects who have risked their careers to expose this information.
   
   http://www.AE911Truth.org

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      Vellurposted 11 years agoin reply to this

      Thank you for taking the time to write and share this fascinating and totally interesting information. I will follow the link and read. Thank you once again.

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   Chloe Micaposted 8 years ago

   Chemical reaction follows the law of conservation of energy, so if heating is required then it is generally considered as an endothermic reaction. If not and the heat release is obvious while conducting experiment, then it is an exothermic reaction.

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