Chem problem?

Question

A 1.00 g sample of an alkaline earth metal chloride is treated with excess silver nitrate. All of the chloride is recovered as 1.38 g of silver chloride. Identify the metal.

Answer 1

Divide 1.38 by the Mr of AgCl. That tells you how many moles of Cl are present, and if you halve it, it tells you the number of moles of the metal chloride.

The Mr of the metal chloride is 1.00 divided by this number of moles. Now take off 71 (for the two Cl atoms) and it leaves you with the Ar of the metal.