Does CO2 have more/less/same potential energy than carbon and oxygen?

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C0balt
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In yesterday's IGCSE science exams I was given the equation:
C2+O2 ---> CO2

Then it asked me "Does CO2 have more, or less potential energy than oxygen and carbon, or does it have the same amount of potential energy?" or something like that.

I had to say more, less or same and then give an explanation.

Well...they need energy to bond together but the reaction is exothermic so releases energy but then when you want to break the CO2 bonds apart you need even more energy
Does that mean it has less potential energy?
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EierVonSatan
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Think about how you might draw an energy diagram to represent an exothermic reaction
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Dynamo123
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(Original post by C0balt)
In yesterday's IGCSE science exams I was given the equation:
C2+O2 ---> CO2

Then it asked me "Does CO2 have more, or less potential energy than oxygen and carbon, or does it have the same amount of potential energy?" or something like that.

I had to say more, less or same and then give an explanation.

Well...they need energy to bond together but the reaction is exothermic so releases energy but then when you want to break the CO2 bonds apart you need even more energy
Does that mean it has less potential energy?
Well, think about it, the reaction is exothermic, energy is given "off" so the product would be, in an energy profile, at a lower level than the reactants. Now to do the opposite reaction, what would you need to do? Give or remove energy?
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C0balt
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(Original post by EierVonSatan)
Think about how you might draw an energy diagram to represent an exothermic reaction
I didn't know what the hell an energy diagram but thanks Mr Google, you sir are amazing and teacher, teach us the whole syllabus please

Apparently product has less PE than the reactants in exothermic reaction...sigh :rip:

It's always like that in exams... I think something and I think it's right in the exam but if I think about it with cool head right after the exam it actually is the other answer :facepalm: I hope it won't affect my grade ._. I'd be so mad if I miss dat A* when I've been getting A* every practice exam beforehand .____.
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EierVonSatan
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(Original post by C0balt)
I didn't know what the hell an energy diagram but thanks Mr Google, you sir are amazing and teacher, teach us the whole syllabus please

Apparently product has less PE than the reactants in exothermic reaction...sigh :rip:
Oh my :p: But yes, if a system is giving out energy, then the systems potential energy falls as shown in those diagrams :yep:

It's always like that in exams... I think something and I think it's right in the exam but if I think about it with cool head right after the exam it actually is the other answer :facepalm: I hope it won't affect my grade ._. I'd be so mad if I miss dat A* when I've been getting A* every practice exam beforehand .____.
It's easy to get confused in an exam situation with this type of thing. Best thing to do is to move on and come back to it instead of going back and forth in your head wasting time
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C0balt
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(Original post by Dynamo123)
Well, think about it, the reaction is exothermic, energy is given "off" so the product would be, in an energy profile, at a lower level than the reactants. Now to do the opposite reaction, what would you need to do? Give or remove energy?
if you mean breaking the bond (i don't even know if its possible but) then you need to give energy to overcome the force of attraction
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Dynamo123
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(Original post by C0balt)
if you mean breaking the bond (i don't even know if its possible but) then you need to give energy to overcome the force of attraction
Exactly. This is a round about way of saying that the product has low P.E and the reactants have higher P.E. To go for the reverse reaction, which in our case would be endothermic, we need to provide energy to take the product to the level of the reactant.

Also, if you are confused about chemistry (which, I admit, is perhaps the most nitpicking idiot out there) you can try http://www.chemguide.co.uk/ They explain most of the basic chemistry concepts in a very engaging way.

Good luck with the exam
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C0balt
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(Original post by Dynamo123)
Exactly. This is a round about way of saying that the product has low P.E and the reactants have higher P.E. To go for the reverse reaction, which in our case would be endothermic, we need to provide energy to take the product to the level of the reactant.

Also, if you are confused about chemistry (which, I admit, is perhaps the most nitpicking idiot out there) you can try http://www.chemguide.co.uk/ They explain most of the basic chemistry concepts in a very engaging way.

Good luck with the exam
thank you!
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