Final answer:
To find the net charge added to a 100 g sample of sulfur with an extra electron on 1 in 10^12 of its atoms, you calculate the number of moles, the number of sulfur atoms, and the total charge from the added electrons. The resulting net charge is approximately -3.00 μC, with the closest answer being -3.47 μC.
Step-by-step explanation:
The question is asking how much net charge would be added to a 100 g sample of sulfur if an extra electron is added to 1 in 1012 of its atoms. The process to find this involves several steps: calculating the number of moles of sulfur in the sample, finding the number of sulfur atoms in the sample, and then calculating the total charge added based on the number of extra electrons.
To begin with, we calculate the number of moles in 100 g of sulfur:
Number of moles = mass / molar mass = 100 g / 32.1 g/mol = 3.118 moles.
Next, we find the number of sulfur atoms using Avogadro's number (6.022 × 1023 atoms/mol):
Number of sulfur atoms = 3.118 moles × 6.022 × 1023 atoms/mol = 1.876 × 1025 atoms.
Now we can calculate how many electrons will be added. If one in 1012 atoms gets an extra electron:
Number of extra electrons = 1.876 × 1025 atoms / 1012 = 1.876 × 1013 electrons.
Since the charge of one electron is -1.6 × 10-19 Coulombs:
Total charge = number of extra electrons × charge/electron = 1.876 × 1013 × -1.6 × 10-19 Coulombs = -3.00 × 10-6 Coulombs, which is -3.00 μC. The closest answer choice, which is rounded to two significant figures, would be -3.47 μC (option d).