Answer:
Concentration of Mg(OH)₂ is 0.600 M
Step-by-step explanation:
Our solution is made by Mg(OH)₂, the solute and waterm as solvent. In the begining we convert the moles to mass:
18.6 g . 1 mol /41.32g = 0.450 mol.
As water is the solvent, the volume for the solution is 750 mL.
We define molarity as the amount of moles of solute, contained in 1 L of solution, but we can also say that molarity are the mmoles contained in 1 mL of solution
M = mol/L = mmol /mL
We convert the mol to mmol → 0.450 mol . 1000 = 450 mmol
M = mmol/mL → 450 mmol / 750mL ⇒ 0.600 M