[StephenD420]

How can I find the formula for the decomposition of cobalt oxalate hydrate? When cobalt oxalate hydrate is heated it forms Co3O4. How can I find the formula from this?

Thanks.
Stephen

[Arkcon]

Can you start by writing it out, for yourself?  You have the formula for the starting material, you heat it to decompose it to something that also has a formula, then what?  You'll have to account for all atoms, so which ones will be left?  Can the be formed into stable molecules you've heard of?  If you can figure it out for yourself, you'll be better off come exam time.  That's how we like to help, on this forum.