inorganic chemistry - Why does hot steam produce MgO instead of Mg(OH)2?

Background research

Question

Why doesn't magnesium hydroxide form when treated with hot steam, instead of magnesium oxide?

Answer

There are two steps in the process:

$\ce{Mg + H2O -> MgO + H2}$

and

$\ce{MgO + H2O <-> Mg(OH)2}$

The equilibrium point in the second step is dependent on the temperature. See file Equilibrium Assemblages for more information.