Final answer:
The atom percent of Sn in an alloy is found by calculating the moles of Sn, determining the total moles of all elements in the alloy, and then dividing the moles of Sn by the total moles and multiplying by 100.
Step-by-step explanation:
To determine the atom percent of Sn (tin) in an alloy, one must first understand that atom percent is a measurement of the proportion of a given element's atoms relative to the total number of atoms in the mixture. The given information states that there are 118.7 g of Sn, and each sample in the provided figure contains 6.022 × 10²³ atoms, meaning 1.00 mole of atoms.
The atomic weight of Sn is 118.71 g/mol, thus 118.7 g of Sn is approximately 1 mole or 6.022 × 10²³ atoms of Sn. If an alloy is composed solely of the elements S, Si, Pb, and Sn in the given gram amounts, you can calculate the total number of moles in the alloy and then find the atom percent of Sn by dividing the moles of Sn by the total moles of all elements. Remember that the atomic weights needed for these calculations are: S (32.065 g/mol), Si (28.0855 g/mol), Pb (207.2 g/mol), and Sn (118.71 g/mol).
First, you would convert the gram amounts into moles for each element. Then, you would add all the moles together to get the total moles in the alloy. Finally, you would divide the number of moles of Sn by the total moles and multiply by 100 to get the atom percent of Sn in the alloy.