How to Calculate Weight Percent Composition of Alloy with Pb and Sn

What is the weight percent composition of an alloy that consists of 6 at% Pb and 94 at% Sn?

What are the atomic weights of Pb and Sn? How can we calculate the weight percent composition based on the given at% compositions?

Weight Percent Composition of Alloy

The alloy has a weight percent composition of approximately 10.02% Pb and 89.98% Sn, as calculated based on the given atomic weights and at% compositions.

To calculate the weight percent composition of an alloy with 6 at% Pb (lead) and 94 at% Sn (tin), we can use the atomic weights of these elements. The atomic weight of Pb is 207.2 g/mol, and that of Sn is 118.71 g/mol.

First, we determine the weight contribution of each element in the alloy. For Pb, with a composition of 6 at%, we calculate its weight as follows:

6 at% Pb means that for every 100 atoms in the alloy, 6 are Pb atoms. So, we have 6 atoms of Pb.

Weight of Pb = 6 atoms × 207.2 g/mol = 1243.2 g

For Sn, with a composition of 94 at%, we calculate its weight as follows:

94 at% Sn means that for every 100 atoms in the alloy, 94 are Sn atoms. So, we have 94 atoms of Sn.

Weight of Sn = 94 atoms × 118.71 g/mol = 11157.54 g

Now, we find the total weight of the alloy by adding the weights of Pb and Sn:

Total weight of the alloy = Weight of Pb + Weight of Sn = 1243.2 g (Pb) + 11157.54 g (Sn) = 12400.74 g

To calculate the weight percent composition for each element, we divide the weight of each element by the total weight of the alloy and multiply by 100:

Weight percent of Pb = (1243.2 g / 12400.74 g) × 100 ≈ 10.02%

Weight percent of Sn = (11157.54 g / 12400.74 g) × 100 ≈ 89.98%