Question

Gold forms a substitutional solid solution with silver. Compute the number of gold atoms per cubic centimeter for a silver-gold alloy that contains 24 wt% Au and 76 wt% Ag. The densities of pure gold and silver are 19.32 and 10.49 g/cm3, respectively. The atomic weight of Au is 196.97 g/mol.

Answer 1

We assume mass to be 100 g and according to percent given we get mass of each in 100 g.

We use density of Ag and Au to get total volume associated with 100 g of solid solution of Au and Ag. Mass of Au calculated is used to get its mole. Now the moles that we get are in volume of 100 g of alloy.

But we need the number of moles in 1 cm³ of this solution. Once we get number of moles of Ag in 1 cm³ , we multiply it by Avogardo’s number and find number of atoms of Au.