Question

Calculate the number of oxygen atoms in a sample of iron(III) oxide. Be sure your answer has a unit symbol if necessary, and round it to significant digits.

Answer 1

The number of oxygen atoms in one mole of iron(III) oxide is calculated by multiplying 3 moles of oxygen by Avogadro's number, resulting in 1.807 x 10^24 oxygen atoms, rounded to three significant figures.

Step-by-step explanation:

To calculate the number of oxygen atoms in a sample of iron(III) oxide (Fe2O3), we need to know the amount of the compound we have in moles. Iron(III) oxide has a molar mass of approximately 159.69 g/mol (55.845 g/mol for iron times 2 plus 16.00 g/mol for oxygen times 3). If we assume we have one mole of Fe2O3, the number of oxygen atoms would be 3 moles (since there are 3 oxygen atoms in the formula).

Using Avogadro's number, which is 6.022 × 1023 atoms or molecules per mole, we multiply the moles of oxygen by Avogadro's number to get the total number of atoms:

3 moles O x 6.022 × 1023 atoms/mole = 1.807 × 1024 O atoms

So, in a sample of one mole of iron(III) oxide, there would be 1.807 × 1024 oxygen atoms, rounded to three significant figures.