Determine the relative amounts (in terms of volume fractions) for a 15 wt% sn-85 wt% pb alloy at 100â°c. the densities of tin and lead at 100â°c are given as follows: ïsn = 7.29 g/cm3 ïpb = 11.27 g/cm3

Volume fraction = volume of the element / volume of the alloy

Volume = density * mass

Base: 100 grams of alloy

mass of tin = 15 grams

mass of lead = 85 grams

volume = mass / density

Volume of tin = 15g / 7.29 g/cm^3 = 2.06 cm^3

Volume of lead = 85 g / 11.27 g/cm^3 = 7.54 cm^3

Volume fraction of tin = 2.06 cm^3 / (2.06 cm^3 + 7.54 cm^3) = 0.215

Volume fraction of lead = 7.54 cm^3 / (2.06 cm^3 + 7.54 cm^3) = 0.785

As you can verify the sum of the two volume fractions equals 1: 0.215 + 0.785 = 1.000

It's not the same dearthe first one is in grams per mole while the other is not