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Balanced Half Equations for Electrolysis

Hi there, I am having a bit of a homework dilemma! I just can't get my head around this question:
" Write balanced half equations for the processes that occur at the electrodes during the electrolysis of this salt solution"

All I know is that at the positive electrode , H+ is going to it and at the negative electrode, Cl- is going to it. Please help!
@TheDoctor11

Hi there, you might find this GCSE Bitesize topic revision link helpful :smile:.
Half equations show the electron transfer.
So first ions are attracted to the electrode of the opposite charge. So Cl- ions go to the positive electrode and H+ ions go to the negative electrodes.

At electrodes, ions want to become atoms again so lose or gain electrons. H+ needs one electron to go back to being a normal atom again. So you would technically represent it like this. (e- being an electron)

H+ + e- -----> H But hydrogen always bond in pairs as H₂. To create two hydrogen atoms though as H₂, two H+ ions need to be used, therefore 2 electrons. So to balance it we would have

2H+ + 2e- ---> H₂

Then you do the exact same thing to get a half equation for chlorine. Chlorine always bonds in pairs also.

2Cl + 2e- ----> Cl₂

And those are balanced half equations (:
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TheDoctor11
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Original post by ivy_entoile
half equations show the electron transfer.
So first ions are attracted to the electrode of the opposite charge. So cl- ions go to the positive electrode and h+ ions go to the negative electrodes.

At electrodes, ions want to become atoms again so lose or gain electrons. H+ needs one electron to go back to being a normal atom again. So you would technically represent it like this. (e- being an electron)

h+ + e- -----> h but hydrogen always bond in pairs as h₂. To create two hydrogen atoms though as h₂, two h+ ions need to be used, therefore 2 electrons. So to balance it we would have

2h+ + 2e- ---> h₂

then you do the exact same thing to get a half equation for chlorine. Chlorine always bonds in pairs also.

2cl + 2e- ----> cl₂

and those are balanced half equations (:


thanks so much!!!

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