To calculate the mass of Fe2S3 with a given number of iron atoms, you need to consider the molar mass and stoichiometry of Fe2S3.
The molar mass of Fe2S3 can be calculated as follows:
Molar mass of Fe = 55.845 g/mol Molar mass of S = 32.06 g/mol
Molar mass of Fe2S3 = (2 * Molar mass of Fe) + (3 * Molar mass of S) = (2 * 55.845 g/mol) + (3 * 32.06 g/mol) = 111.69 g/mol + 96.18 g/mol = 207.87 g/mol
Now, to find the mass of Fe2S3 with 1.25×10^15 iron atoms, we'll use the Avogadro's number.
Avogadro's number (Na) = 6.022 × 10^23 atoms/mol
First, calculate the number of moles of Fe2S3:
Number of moles = Number of atoms / Avogadro's number = 1.25×10^15 atoms / (6.022 × 10^23 atoms/mol) = 0.002076 mol (approximately)
Finally, calculate the mass of Fe2S3:
Mass = Number of moles × Molar mass = 0.002076 mol × 207.87 g/mol = 0.431 g (approximately)
Therefore, the mass of the Fe2S3 sample containing 1.25×10^15 iron atoms is approximately 0.431 grams.