Question

Calculate the molarity of 28.1 g of MgS in 813 mL of solution.

Answer 1

molar mass of Mg = 24.3 and S = 32,

The molar mass of MgS is : MgS = 56.3 g/mol
No. of moles of MgS = mass of MgS/ molar mass of MgS

                                  = 28.1/56.3 = 0.499 moles.

Molarity = No. of moles / volume in Liter

               = 0.499/0.813 L = 0.614M

Hence, the molarity of the given solution is = 0.614 M