Balancing equation, please help!

[katwoman]

HCl + Mg2(OH)2 --> MgCl2 + H20

Answer: one mole MgCl, two moles H20

I can't seem to figure out how to get the correct answer, which I included.

[ChenBeier]

First it is Mg(OH)2

Magnesium bond to two OH-groups.

Now you add hydrochloric acid HCl

each H will combine with OH to water H2O

Result

Mg(OH)2 + 2 HCl => MgCl2 + 2 H2O