Answer:
HBr + Mg(OH)2 —> MgBr2 + H2O.
To balance the above, we must do a head count of the individual atoms present to ensure they balance on both sides of the equation. To get the balance equation, add 2 in front of HBr and 2 in front of H2O as shown below:
2HBr + Mg(OH)2 —> MgBr2 + 2H2O
We can see clearly that the numbers of the individual atoms on the left side is the same on the right side
