The Student Room Group

Born Haber cycle

In born haber cycle, why does the direction of arrow matters? (eg. the arrow needs to point downwards for the first electron affinity) I thought the charges on the values represent if they are endo or exothermic, doesn't the arrow just represent the flow?

Thanks a lot!
Original post by SS1234567890
In born haber cycle, why does the direction of arrow matters? (eg. the arrow needs to point downwards for the first electron affinity) I thought the charges on the values represent if they are endo or exothermic, doesn't the arrow just represent the flow?

Thanks a lot!


The arrows are indicative of whether a process is exothermic or endothermic. If a process is endothermic, the arrow points up. If a process is exothermic, the arrow points down. This is most probably because not all Born-Haber cycles have enthalpy values quoted on them.
Original post by TypicalNerd
The arrows are indicative of whether a process is exothermic or endothermic. If a process is endothermic, the arrow points up. If a process is exothermic, the arrow points down. This is most probably because not all Born-Haber cycles have enthalpy values quoted on them.


Thanks a lot for replying! So if there’s values on it, does the arrow just represent the flow then?
Original post by SS1234567890
Thanks a lot for replying! So if there’s values on it, does the arrow just represent the flow then?


Regardless of whether a value is given or not, it will represent whether the process is exothermic or not. I guess you could also say it represents the flow, but that’s largely coincidence.
Original post by TypicalNerd
Regardless of whether a value is given or not, it will represent whether the process is exothermic or not. I guess you could also say it represents the flow, but that’s largely coincidence.


I see, thanks a lot for the help!

Quick Reply

Latest