Answer :
To find out how many grams of iron(III) oxide (Fe₂O₃) are in 0.500 moles of this substance, we need to use the molar mass of Fe₂O₃.
First, let's calculate the molar mass of Fe₂O₃. Iron (Fe) has an atomic mass of approximately 55.8 g/mol, and oxygen (O) has an atomic mass of approximately 16.0 g/mol.
The chemical formula of iron(III) oxide is Fe₂O₃, which means it contains two iron atoms and three oxygen atoms. We calculate the molar mass as follows:
Iron:
[tex]2 \times 55.8 \text{ g/mol} = 111.6 \text{ g/mol}[/tex]Oxygen:
[tex]3 \times 16.0 \text{ g/mol} = 48.0 \text{ g/mol}[/tex]Total Molar Mass of Fe₂O₃:
[tex]111.6 \text{ g/mol} + 48.0 \text{ g/mol} = 159.6 \text{ g/mol}[/tex]
Now that we know the molar mass of Fe₂O₃ is 159.6 g/mol, we can calculate the mass of 0.500 moles of Fe₂O₃ using the formula:
[tex]\text{mass} = \text{moles} \times \text{molar mass}[/tex]
Substitute the values:
[tex]\text{mass} = 0.500 \text{ moles} \times 159.6 \text{ g/mol}[/tex]
[tex]\text{mass} = 79.8 \text{ g}[/tex]
Therefore, there are approximately 79.8 grams of iron(III) oxide in 0.500 moles of the substance.
The correct option from the multiple-choice answers is closest to 79.9 g, so the answer is 79.9 g.