Ionic Equasions

One thing in chemistry I've never been able to get my head around is ionic equasions, I don't see how they work. I mean, I'm told to only use the ions involved in the reactions and leave out spectator ions, but how do I tell which is which?

I know that they're similar to half-equasions in REDOX reactions, but I'm not sure if I fully understand them either XD

If anyone could explain it to me in simple terms it would be greatly appreciated.

ionic equations...?


I don't think I've done these. Yet. Possibly. XD Could I be given an example? Because I might actually know what you are talking about... not know it.

I was meant to have done them last year, and the year before and hadn't a clue either time, goodness knows how I did so well in my exam XD

The question I was given that made me realise I didn't know was 'Work out the ionic equasion for the complete neutralisation of sulphuric acid by potassium hydroxide.'

An example? There's one in my revision guide, but it's not explained -___-"

That was

Cr2O72- + H+ + e- ----> Cr3+ + H2O

But there wasn't a full equasion for me to compare it to, so it made no sense to me XD