What is the density of 18.0-karat gold that is a mixture of 18 parts gold, 5 parts silver, and 1 part copper? (These values are parts by mass, not volume.) Assume that this is a simple mixture having an average density equal to the weighted densities of its constituents.

Step-by-step solution Step 1 of 9 If total mass of a mixture is divided by total volume; it gives the value of average density of the mixture. Step 2 of 9 Density of a substance is mass of that substance per unit volume of the substance. Therefore, …… (1) Here, is density, is mass and, is volume. Step 3 of 9 From equation (1), volume of 18 g gold is, Step 4 of 9 Substitute for and for . Step 5 of 9 From equation (1), volume of 5g sliver is, Substitute for and for .