What is the molarity of the solution that is formed when 18.6 g of magnesium hydroxide (formula mass 41.32 g/mol) is dissolved in water to make 750.0 mL of a Mg(OH)2(aq) solution

Concentration of Mg(OH)₂ is 0.600 M

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

the millers tale is the answer.