Answer
The formula weight for magnesium hydroxide is 58.3 grams/mol.
Work Step by Step
In every mole of Magnesium Hydroxide there is:
1 mol of Magnesium ions
2 mol of Oxygen ions
2 mol of Hydrogen ions
These quantites must be multiplied by their weights per mole and then added to yield there formula weight
1 mol of Magnesium ions X 24.3 gram/mol = 24.3 grams of Mg
2 mol of Oxygen ions X 16 grams/mol = 32.0 grams of O
2 mol of Hydrogen ions X 1 gram/mol = 2.0 grams of H
Your result when these values are added up is 58.3 grams/mol of magnesium hydroxide
