Question

A 1.59-g sample of a metal chloride, mcl2, is dissolved in water and treated with excess aqueous silver nitrate. the silver chloride that formed weighed 3.60 g. calculate the molar mass of m.

Answer 1

56.30 The atomic mass of Ag is 107.87. The atomic mass of Cl is 35.45. The molecular mass of AgCl is therefore 143.32. 0.025 mols of AgCl were produced. This required .0125 mols of the original metal chloride since it has 2 chlorine atoms per molecule and AgCl only has one per molecule. The molecular mass of mCl2 must be 127.2 in order for 1.59g of mCl2 to be .0125 mols. The molecular mass of m can be calculated by subtracting the molecular mass of 2 chlorine atoms 127.2-35.45-35.45=56.30