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# Help with exo/endo thermic reactions

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1. i dont understand how is that endothermic when endothermic means heat travels into the the system and the experiment above shows a temperature drop???!!?!?
2. (Original post by CorpusLuteum)

i dont understand how is that endothermic when endothermic means heat travels into the the system and the experiment above shows a temperature drop???!!?!?
Let's say a reaction occurs, it's endothermic so heat will be taken in, meaning there will be a decrease in the surrounding temperature. Whereas if it was exothermic, heat would be released during the reaction thus the temperature would increase.

I don't know how to explain this in the most scientific way but can you understand it any better now?

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3. (Original post by Changing Skies)
Let's say a reaction occurs, it's endothermic so heat will be taken in, meaning there will be a decrease in the surrounding temperature. Whereas if it was exothermic, heat would be released during the reaction thus the temperature would increase.

I don't know how to explain this in the most scientific way but can you understand it any better now?

Posted from TSR Mobile
Yes that's right. I did GCSE a year ago now, but from what I remember, Exothermic reactions have a larger amount of stored energy than is needed for activation of the the experiment. So the excess energy is expelled into the surrounding area as heat. That why an Exothermic reaction will feel hot if you touch the beaker or whatever. (Just think EXO- heat exits)

In Endorhermic reactions, there isn't enough stored energy compared the amount required to activate and maintain the reaction. Therefore. Heat energy is drawn in from the nearby surroundings to make up for the shortfall. That's why the Beaker and things feel cold in endothermic reactions.

That vast majority of reactions are exothermic too.

Hope this helps
4. (Original post by Gold-Confetti)
Yes that's right. I did GCSE a year ago now, but from what I remember, Exothermic reactions have a larger amount of stored energy than is needed for activation of the the experiment. So the excess energy is expelled into the surrounding area as heat. That why an Exothermic reaction will feel hot if you touch the beaker or whatever. (Just think EXO- heat exits)

In Endorhermic reactions, there isn't enough stored energy compared the amount required to activate and maintain the reaction. Therefore. Heat energy is drawn in from the nearby surroundings to make up for the shortfall. That's why the Beaker and things feel cold in endothermic reactions.

That vast majority of reactions are exothermic too.

Hope this helps
Appreciate the more detailed answer, very helpful it's been years since I've done any of this and I'm useless at chemistry haha

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5. (Original post by Changing Skies)
Appreciate the more detailed answer, very helpful it's been years since I've done any of this and I'm useless at chemistry haha

Posted from TSR Mobile
Lol same I think I sat this exam in year 10. Winged my way to an A because our chemistry teacher was awful 🙈
I don't take any science or maths A-Levels either. Must've done something right to remember this because it used to confuse the life out of me ahaha
6. (Original post by Changing Skies)
Let's say a reaction occurs, it's endothermic so heat will be taken in, meaning there will be a decrease in the surrounding temperature. Whereas if it was exothermic, heat would be released during the reaction thus the temperature would increase.

I don't know how to explain this in the most scientific way but can you understand it any better now?

Posted from TSR Mobile
(Original post by Gold-Confetti)
Yes that's right. I did GCSE a year ago now, but from what I remember, Exothermic reactions have a larger amount of stored energy than is needed for activation of the the experiment. So the excess energy is expelled into the surrounding area as heat. That why an Exothermic reaction will feel hot if you touch the beaker or whatever. (Just think EXO- heat exits)

In Endorhermic reactions, there isn't enough stored energy compared the amount required to activate and maintain the reaction. Therefore. Heat energy is drawn in from the nearby surroundings to make up for the shortfall. That's why the Beaker and things feel cold in endothermic reactions.

That vast majority of reactions are exothermic too.

Hope this helps
I still understand why the temperature dropped. D:
7. (Original post by CorpusLuteum)
I still understand why the temperature dropped. D:
Do you mean you don't understand why the temperature drops? I can try to explain it again in a different way if that's the problem
8. (Original post by Gold-Confetti)
Do you mean you don't understand why the temperature drops? I can try to explain it again in a different way if that's the problem
Yeah, so what is the the heat going into if it is endothermic? Idk, where the heat has gone and why the waters temperature is dropping even though endothermic means for heat to be going in to something (making it hotter)
9. (Original post by CorpusLuteum)
Yeah, so what is the the heat going into if it is endothermic? Idk, where the heat has gone and why the waters temperature is dropping even though endothermic means for heat to be going in to something (making it hotter)
The heat (energy) is going into the molecules that are forming, and the heat comes FROM the water which is why the temperature drops
10. (Original post by Poooky)
The heat (energy) is going into the molecules that are forming, and the heat comes FROM the water which is why the temperature drops
oh, starting to make sense... Um, if you're on a computer could you draw it for me on http://sketchtoy.com/ Because I can't actually make sense of it D:
11. (Original post by CorpusLuteum)
Yeah, so what is the the heat going into if it is endothermic? Idk, where the heat has gone and why the waters temperature is dropping even though endothermic means for heat to be going in to something (making it hotter)
Okay, if the reaction is endothermic, it needs to use the energy from the heat in the area around it, so literally- the heat stored in the beaker and the air/ stuff around it. The heat is drawn in to the reaction. The heat will go into the reaction but it won't feel hot because the energy will be used to plug the gap in energy needed to complete the reaction.
The jar the reaction is happening in, and the immediate area around it will feel cold because the heat has been taken in by the chemicals that are reacting and used to complete the reaction. The heat energy is used for the purpose of complete ong the reaction and not for heat so it will not feel hot.

Yes the heat goes in, but think of the beaker as a threshold where once the heat enters it changes into something else, and doesn't exist as heat anymore. That energy is still there, it's just no longer hot. That's why it feels cold- because the heat is sucked in and used in the reaction so the things that were warm will now feel cold because he heat energy is no longer there.

I hope this clarifies it for you.
12. (Original post by Gold-Confetti)
Okay, if the reaction is endothermic, it needs to use the energy from the heat in the area around it, so literally- the heat stored in the beaker and the air/ stuff around it. The heat is drawn in to the reaction. The heat will go into the reaction but it won't feel hot because the energy will be used to plug the gap in energy needed to complete the reaction.
The jar the reaction is happening in, and the immediate area around it will feel cold because the heat has been taken in by the chemicals that are reacting and used to complete the reaction. The heat energy is used for the purpose of complete ong the reaction and not for heat so it will not feel hot.

Yes the heat goes in, but think of the beaker as a threshold where once the heat enters it changes into something else, and doesn't exist as heat anymore. That energy is still there, it's just no longer hot. That's why it feels cold- because the heat is sucked in and used in the reaction so the things that were warm will now feel cold because he heat energy is no longer there.

I hope this clarifies it for you.
Ah! Yes! I understand it!
Thank you so much.
13. (Original post by CorpusLuteum)
Ah! Yes! I understand it!
Thank you so much.
Glad to be of service 😊 I hope your exams go well

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