If you mean hydrate as in <em>MgSO4 · 7H2O, </em>then simply find the molar mass of each element you see.
For the example above, that means you would add the molar mass (found on the periodic table) of Mg, then S, then 4(O), 14(H), and 7(O).
The results would be your molar mass for the hydrate.
I hope this is what you meant by your question!
Answer:
first the right answer is
Li + H2O = LiOH + H2O
then to balance it...
2 Li + 2 H2O = 2 LiOH + H2
so that we can have both side of the equation to be equal....
HOPE ITS HELPS....