# Is there a difference between hydrated oxides and hydroxides?

My guess is that they are different.

I think hydrated oxides would have a lattice with the cation and oxide anions as lattice points and molecules of water trapped in interstitial spaces, while hydroxides would have the cation and hydroxide anions as lattice points with no water molecules in interstitial spaces.

• I think that when we talk about bases, we immediatly have to do with hydroxides because they contain the hydroxide group OH-. Hydrated oxides on the other hand can be only simple oxides who contain also Hydrogen. I didn't find anything on the internet so this is just a thought. – Ndrina Limani May 6 '15 at 20:39
• $\ce{Mn(OH)2}$ is a hydroxide while $\ce{MnO(OH)2}$ is a hydrated oxide. – Nilay Ghosh Jun 20 '16 at 10:55
• Maybe hydrated oxides don't even have a lattice; that's not important. What is important is their non-stoichiometric composition. – Ivan Neretin Mar 15 '17 at 5:34