Answer
The molar mass for $Mg(OH)_2$ is equal to 58.33 g
Work Step by Step
1. Identify the molar mass for each element in this compound:
$Mg: 24.31$ g
$O: 16.00$ g
$H: 1.008$ g
2. Multiply each one of them by their respective subscript number. For the elements that are enclosed in brackets, also multiply them by the subscript of the brackets:
$Mg: 24.31$ g
$O: 16.00$ g * 2 = 32.00 g
$H: 1.008$ g * 2 = 2.016 g
3. Calculate the total sum of these values:
$24.31 g + 32.00 g + 2.016 g = 58.33g$
