You are Here: Home

# Balanced Half Equations for Electrolysis watch

1. 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!
2. TheDoctor11

Hi there, you might find this GCSE Bitesize topic revision link helpful .
3. 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 (:
4. (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!!!

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: April 12, 2016
Today on TSR

### Three reasons you may feel demotivated right now

...and how to stay positive

### Can I get A*s if I start revising now?

Discussions on TSR

• Latest
Poll
Discussions on TSR

• Latest

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE