Final answer:
To determine the number of Sc atoms in 0.25 mol of scandium(III) oxide, we calculate the number of moles of Sc in 0.25 mol of Sc₂O₃ and then multiply by Avogadro's number to get the number of Sc atoms.
Step-by-step explanation:
To determine the number of Sc atoms in 0.25 mol of scandium(III) oxide, we need to use Avogadro's number and the molar mass of Sc. The molar mass of Sc is 44.9559 g/mol. Avogadro's number is 6.022 x 10²³ atoms/mol.
First, calculate the number of moles of Sc in 0.25 mol of Sc₂O₃:
0.25 mol x (2 mol Sc / 1 mol Sc₂O₃) = 0.5 mol Sc
Then, calculate the number of Sc atoms:
0.5 mol Sc x (6.022 x 10²³ atoms Sc / 1 mol Sc) = 3.011 x 10²³ atoms Sc