Chapter 13 - Properties of Solutions - Exercises - Page 568: 13.43a

0.0146 M

We have 0.540g of Mg(NO3)2 and in 250mL. To find the molarity, we need the moles of Mg(NO3)2 per liter so we need the molar mass of Mg(NO3)2 to find the moles: Mg is 24.3 g/mol N is 14 g/mol O is 16 g/mol 24.3 + (14 + 3*16) * 2 = 148.3 g/mol Then we have 0.540g * (1mol/148.3g) = 0.0036 moles Then we have 250mL, or 0.250L so the molarity is 0.0146 M